Idk I feel like it's more complicated than that. Based on all the details, I think that emotions were running high and In the heat of the moment when they were both participating in sexual activities, the next step is naturally intercourse, but it was probably their first time in a male to male relationship so they didn't realize that they have to slowly prepared and stretch them out so that it doesn't tear and then in the end when he saw the blood, he puked because it was so shocking and jarring and probably brought up maybe a traumatic old memory or it made him feel like he rushed into it and really didn't consider his partner. I feel like he was so ashamed of himself to the point of throwing up. Then the other guy that was bleeding probably felt like he was puking because he thinks he's disgusted and regrets the sex and that's why he swatted his hand away, but I don't think that's the case. I think it's a miscommunication. . . Or I could be totally wrong. ╮( ̄▽ ̄)╭
No I think it’s like…. They started the intimacy but the bottom hadn’t really fully consented and the top didn’t ask. The bottom was unsure and didn’t really know how it worked but trusted the top, seemed like he just went along with it because he really didn’t know how to react then when he finally snapped out of it he said it hurt and to stop but the top continued. When the top finally snapped out of his lust I got the impression he puked up because he hadn’t expected himself to treat the guy he loved or at least cared for so roughly. Ngl the bruise on his cheek, I have a suspicion it could have been from an ex? So he was taking his frustration out on the bottom then got physically sick because it was so hateful. There’s multiple reasons why he could have puked…but yeah the bottom was so traumatised. It actually makes sense why he puked with the younger guy. The first love is just disgusting tho, if there was ever a time for forgiveness it would have been when they were younger and tbh if the bottom did forgive him which I think he did it wouldn’t result in a relationship (which it didn’t) and I feel the og love never accepted that.
Yeah, I felt like he puked because of a blood itself also, some kind of trauma like you said, but of course all of that doesn't change the fact that it was rape, and even if they addressed that somehow later in the past, bottom is definitely still traumatized, cannot blame him, because that was an awfull first time and first love thankfully bottom didn't end up with that asshole (hopefully it will stay like this!), and yeah, he has right to feel bad about all of that, and honestly, I hope that rapist will disappear from the picture soon and author will adress that, because no matter what was your intention/trauma, if you force yourself on someone, you are a rapist, what's done is done, and no bad past can excuse that...
Now just looking forward for the bottom to be happy with his new young top full of love!

HES A FUCKING RAPIST?! THE AUDACITY TO RAPE SOMEONE THEN PUKE AS IF YOU WERE FORCED TO SWXUALLY ASSAULT THEM AHH I HATE MEN!! i wonder if this will be treated with the gravity it deserves…i have faith in this author.
(neither the two main characters are rapists for people who haven’t read this yet don’t let this discourage you)