The Snack Pack very much make it their mission to hear the laugh again, tho. That was adorable! Who knew Branch was such a cutie!? They did, but like... they had only just started scratching the surface. The laugh came as a huge shock for them because they were expecting a dep chuckle to be his laugh or for him to groan and do his little kicks and stomps.
Bramch for his part probably let out the laugh, had an 'oh shit' moment when he realized what he did, and started covering his mouth and trying to hide his face in mortification at laughing at one of Creek's jokes of all things in earshot of the other trolls! He's supposed to be a loner bad boy type, not giggle like a schoolgirl!!
It’s definitely embarrassing for sure but not as embarrassing as Creek realizing how cute he found that laugh. He also gets a bit of an inflated ego over it and now Branch has to hears jokes about how he’s being shellfish keeping that laugh all to himself like that. Branch is mad because he just learned that he likes puns and it’s Creek’s fault.
Now I’m just picturing Creek having a scrubs moment:
Creek: Wait, is he into me? Quick, make a bad joke and see if he laughs. [to Branch] Did you hear the one about the skeleton who couldn't go to the party? He had no body to go with.
Branch: [laughs] That's funny.
Creek: Well, that's not a fair test, that joke's hilarious.