Responses

My understanding is that he wasn't mad AT the seme. But he was getting a lot of new devastating information at once, coupled with all of your points about his shitty life, he just had a lot of emotions going on and seme was the only one involved in all of it. He didn't have anyone else to grieve/take these emotions out on so the seme just became the target.
Not exactly the healthiest way to cope but they figure it out so
I'm just want clarification, WHY is the uke pressed at seme???
Is the uke upset coz his parents were killed/hurt?
Coz his parent(s) dying has NOTHING to do with seme, he was a KID
Does he thinks seme doesn't like him and just feels pity/indebted to him!?!? Coz if hes pressed he doesn't like him back (he does), what right do he have to be upset?
Is he mad he didn't save him before from his messed up family??? Coz seme didn't even know that was happening to him and thought he WAS protecting him from his crazy dad (who tried to kill him the second the dad found out seme and use talked)
The ONLY rational thing I can think of is seme not telling uke about everything, the uke had the right to know and is COMPLETELY valid in being upset about that, but why have rage sex??? Why bring sex into it at all??? Why is his 1st thought "he was only using me for my body" AS IF THE UKE WASNT DOING THE EXACT SAME THING?!?!?! (tho both have mutual feels for each other, neither of them knows it at this point)