CW: this little snippet discusses my thoughts on Everlark's first time, 18+ only
So I'd imagine like everyone else that it's kinda awkward, not uncomfortable but the way you would expect two virgin adults who have gone through lots of trauma to be for their first time.
I definitely do think that it would unlock something in them after their firstime, even with Peeta who would know a little bit more as his brothers described in detail to him what sex is like, still becomes insatiable like Katniss.
I also think she would basically alert everyone in D12 the next morning, people can just tell by the look on her face what went down. The subtle pride on Peetas face is not subtle at all and people either clap him on the back or refuse to look at them.
Along with that I think it's funny to imagine Peeta panicking about Kat bleeding for their first time (I know it doesn't happen to everyone but whatev), and basically running rampant in his mind if he hurt her.
And lastly, the whole of D12 chips in to get Haymitch earmuffs, cos they know these bitches ain't gonna be quiet