But what ab semes trauma bc I genuinely have no clue what was going on there 💀

All his life he's been misunderstanding other's intentions and feelings. Every time he fell for someone and thought it was mutual, he'd end up cruelly rejected with a "how could you even think of that this way in the first place?!". So he just gave up on flirting and love cause he's bound (in his mind) to misunderstand and ruin the friendship (or whatever there is) again.