The backstory explains a lot to how his behavior and ego came to be. Especially the whole "need to sleep with people bc of my jinx" part. Does this justify his past and present actions? Hell no, but he will learn soon enough like every other human/fictional character out there ╮( ̄▽ ̄)╭
If he wasn't already mad before, he's definitely gonna crash out once he sees what they did to our girl