The episode opens with a distant view of the Heeler house, then cuts to Bandit and Chilli's bedroom, then a top-down view of the family on the bed. They are playing a guessing game.
Bluey: So it's a vegetable, we all like it, and it starts with 'B'?
Bingo: Yes.
Bluey: Broccoli?
Bingo: No.
Chilli: Beetroot?
Bingo: No.
Bandit: Beans?
Bingo: Uh-uh.
Beat, Bluey thinks for a while.
Bluey: Booger-beans?
Bingo giggles.
Bandit and Chilli: Bluey!
Chilli: Booger-beans aren't a vegetable!
Bingo squeals and laughs.
Bandit: Aw, this is impossible!
Chilli: We give up. What is it, Bingo?
Bingo: "Botato"!
All, except Bingo: Aww, Bingo!
Bingo: What?
Bluey: "Potato" starts with a 'P'!
Bingo: Oh. Hehehe!
Chilli: (picks up Bingo and holds her upside down) Come here! Ooh, look at this cute little bottom! (mildly taps Bingo's bum)
Bingo: (laughing) I need the toilet!
Chilli: (lets go of Bingo) Oh, okay!
Bandit: Me first! (quickly gets up, grabs a pillow, and hits Bingo with it to stop her as he casually walks to the bathroom)
Bingo: Hey! (giggles)
Chilli: Are you busting, Bingo?
Bingo: Nah, not really. (crawls and lies next to Bluey)
Bluey: (to her mum) Can we play "Three in the Bed and the Little One Said" while Dad's in the dunny?
Bingo: (excitedly) Yeah!
Chilli: (concerningly) Bluey. Can you say, "toilet" instead of "dunny", please?
Bingo: (to her mum) Why can't we say, "dunny"?
Bluey: Is it a rude word?
Chilli: No, it's not a rude word. I just prefer "toilet".
Bingo: Would the Queen say, "dunny"?
Chilli: Uh, no. It is not the word the Queen would use.
Bingo: Then I'm not saying it either.
Bluey: Chloe's parents let her say it.
Chilli: Well, then that's fine for Chloe. She can say it.
Bluey: But, how come she can say it and we can't?
Chilli: Because different families have different rules. And in this family, we don't say, "dunny".
Toilet flushes at a distance, Bandit returns from the toilet.
Bandit: Dunny's free.
Bingo and Bluey laugh and squeal.
Bingo and Bluey: (point at Bandit) Dad said it! Dad said it!
Bandit: Said what?
Chilli: I was just telling Bluey to say, "toilet" instead of "dunny".
Bandit: What's wrong with "dunny"?
Bingo: It's not the word the Queen would use.
Bluey: And if we can't say it, then you can't say it, Big Daddy!
Bandit: Right, so, we can't say, "dunny"?
Bingo and Bluey: No.
Bandit: But "booger-beans" is fine?
The kids laugh and giggle.
Chilli: Bandit.
Bandit: Whatevs. The toilet is free.
The kids laugh some more.
TITLE CARD: "DUNNY"
Bluey: This episode of "Bluey" is called, "Dunny"!
END TITLE CARD
Bingo: I'm just going to the toilet.
From behind her, Bandit cheekily pulls her leg as she is about to go, making her giggle.
Bandit: Oh, Bingo, have you not learned to walk yet?
Bingo: Yes, I (leg pulled again) h-a-a-ave! (giggles)
Bandit: (to the other family members) Did we not teach this kid to walk?
Chilli: (slightly amused) Let her go to the toilet!
Bandit lets go of Bingo and she runs off to the toilet.
Bandit: (pretending to be impressed) Ah! Our child is taking her first steps! I'm so proud!
Bluey: Mum, am I allowed to say, "dun-eep"?
Chilli: No, Bluey.
Bluey: But I'm not saying, "dunn-y", I'm saying, "dun-eep". I made it up.
Chilli: Then yes, you can say it.
Bluey: (triumphantly) Oos!
Chilli: But if you make up words, no-one will know what you're talking about.
Bluey: Dad will. Watch.
Bluey gets near her dad and prods him.
Bandit: Huh?
Bluey: (to her dad, gibberish)
Bandit: Wow! Are you serious?!
Bluey: (gibberish)
Bandit: I've never considered it at that angle before!
Bluey: (gibberish)
Bandit: (contemplating) This changes everything.
Bluey: (giggles) (to her mum) See?
Chilli: You're both crazy.
Bluey: Do we get in trouble if we say, "dunny"?
Chilli: Yeah, you'll get squish-squashed.
Bluey: What's "squish-squashed"?
Chilli: Well, say "dunny" and find out.
Bluey: Ooh! Dunny!
Chilli snaps her fingers.
Bandit: (rolls over his daughter, making her laugh) Squish-squash!
Chilli: Clear?
Bluey: Yes. But what if you say it?
Chilli: I'll never say it.
As they speak Bingo has finished using the bathroom and crawls under the blanket, just beside her mum.
Bingo: (moving her mum's lips, as if she "says" what Bingo says) "Oh man, Bingo's taking ages in the Dunny!"
Bandit giggles, he and Bluey point at Chilli
Bluey: Mum! Mum! You said, "dunny"!
Chilli: (surprised) It wasn't me!
Bingo: (as before) "Maybe she fell in the dunny!"
Bandit and Bluey: (giggle) She said it again!
Bandit: Yes! (giggles some more)
Chilli notices what's been going on and picks up her youngest daughter from under the blanket.
Chilli: (to Bingo, who is giggling) Come here, you little munchkin! (kisses her and places her between her and Bluey)
Bluey: I think if you say it, we should get chocolate.
Chilli: Okay. Deal!
Bingo squeals upon hearing it
Bluey: Bingo, we have to make Mum say it!
Bingo: Okay, but how?
Bluey: Ooh, I know. Let's play "Pass It On"! Move it, Big Daddy, you're swapping with me! (Bluey gets under the sheets and swaps with her dad.) Okay, ready? All, but Bluey: Ready!
Bluey: (whispers to Bandit) "I like pink biscuits for my morning tea especially if I'm riding my horse to the moon because I like the moon in the morning!"
Bandit: (whispers to Bingo)
Bingo: (whispers to her mum)
Bluey: Ok, go Mum. What did I say?
Chilli: Um, "good morning, I like the moon's biscuits, cause they're better than the moon, and it's morning tea"?
Bandit: No!
Bingo shakes her head and Bluey giggles
Bluey: No, that wasn't it, Mum!
Chilli: Well, what did you say?
Bluey: Uh, "I like...", um... I forget!
Bandit: (tickles Bluey) Keep it simple!
Bingo: My turn!
Bluey: Alright, everyone swap; Mum, you stay there!
Chilli: Okay.
The kids go under the blanket and change position, again at the expense of their dad's comfort. The order is now Bingo, Bluey, Bandit, Chilli.
Bluey: Okay, Bingo. You know what to do!
Bingo: (whispers to Bluey) "Oh man, I need the dunny."
The kids giggle.
Bluey: (whispers to her dad) "Oh man, I need the dunny."
Bandit: (whispers to Chilli) "Oh man, I need the dunny."
Bingo: (to her mum) What did I say?
Bluey: Yeah, what did she say? And you have to say it out loud!
Chilli: "I ran to feed the bunny"?
Bluey and Bingo: No!
Chilli: "So sad, you feed my tummy"?
Bluey and Bingo: No!
Bingo: That wasn't it!
Bluey: She said, "Oh man, I need the dunny"!
Bandit: (rolls on Bluey again) Squish-squash!
The kids laugh.
Chilli: Okay, okay, that's enough squish-squash!
Bandit rolls off. Bluey sighs in relief.
Bluey: Oh, I wish we could say, "dunny".
Chilli: Oh yeah, why's that?
Bluey: I just like it. It rhymes with "funny"!
Chilli: Look. I just want us to use nice words. So everyone thinks we're a nice family.
Bluey: (considering) Oh.
Chilli: Is that an okay thing to want?
All but Chilli: Yeah, that's okay.
Chilli: Thank you.
Bingo: Let's play "Four in the Bed"!
Bandit and Chilli: Okay. Bingo and Bluey: Hooray!
All but Bandit swap places again, this time the order is: Chilli, Bluey, Bandit, Bingo.
Bingo: Ready?
All but Bingo: Ready!
All: "The were four in the bed, and the little one said,"
Bingo: "'Roll over! Roll over!'"
All: "So they all rolled over and one fell out!"
Chilli falls off, everyone but her laughs.
Bluey, Bandit and Bingo: "The were three in the bed, and the little one said,"
Bingo: "'Roll over! Roll over!'"
Bluey, Bandit and Bingo: "So they all rolled over and one fell out!"
Bandit "pushes" Bluey off her bed and lands on her mum. The kids laugh.
Bandit and Bingo: "The were two in the bed, and the little one said,"
Bingo: "'Roll over! Roll over!'"
Bandit: "But the big one said, 'nah!'"
Bingo: Hey! Roll over!
Camera goes to Chilli and Bluey beside the bed as Bingo and Bandit can be audibly heard on the background as the former tries to push the other off the bed and the latter rejecting.
Bluey: Mum, our family rules are to not say, "dunny", right?
Chilli: That's right.
Bluey: 'Cause "toilet"'s a better word.
Chilli: Well, I think so.
Bluey: And Chloe's family rules are that they can say, "dunny".
Chilli: Yes.
Bluey: So does that mean our family rules are better than Chloe's family rules?
Chilli: Well, um... No. They're just different.
Bluey: But you said "toilet" is better.
Chilli: Um, yeah. I-I did.
Back to the bed, Bingo finally gets her dad off the bed.
Bingo: Get out!
Bandit: Oof! (lands on his daughter and wife)
Chilli: Bandit!
The kids squeal and laugh.
Bingo: "There was one in the bed, and the little one said, 'Good night!'" (giggles as she wraps herself tightly in the blanket"
Bluey: And one more question. Is our family better than Chloe's family?
Chilli: No!
Bingo: (climbs over her dad) Mum, can I still say, "dunny" in my head?
Chilli: (exhausted) Oh, booger-beans. Alright, new family rule! We can all say, "dunny".
Bluey and Bingo: Hooray!
Chilli: Just not in front of the Queen.
All but Chilli: (chanting) Dunny! Dunny! Dunny!
Bluey: Thanks, Mum.
Chilli: That's okay. It's not like it's a naughty word.
Bluey: (off-screen) Chloe isn't allowed to say, "naughty", she has to say, "cheeky"!
Chilli: (off-screen) Well, there you go.
The episode ends with a distant view of the house once again.