My ds (now nearly 16) definitely went through this phase of male entitlement/resentment of females at age 14.
I used to pull him up on it constantly: for example, I'd ask him to clear the table/walk the dog/get me something from the shop & he'd instantly be looking round for a younger sister to pass the chore onto; I'd sharply tell him that he was being a sexist git expecting to delegate boring tasks to the nearest female.
It wasn't particularly constructive, as ds believed that sure, he was being lazy & rude, but in his head he would have been just as much of an arse if he'd had a younger brother to harass into doing stuff!
So as far as he was concerned it was a case of 'mum ALWAYS sticks up for the girls, mum is really the sexist one, woe is me, I'm so persecuted for being a boy.'
Once we'd talked through it, & broken that cycle, he did concede that to an extent his sense of entitlement was probably down to us living in a culture (not U.K.) where boys are treated like superior beings to their sisters.
& I had to admit I did jump on him more than if dd1 was being horrid to dd2, because I subconsciously reacted 'Ah! Ds is pushing younger sisters around because male socialisation! Stamp on that!' & that he also had a tiny bit of a point...
So I wonder - what is your household like in terms of males/females? My ds found being the only male from age 10 onwards quite challenging, & whilst it did make him behave like a dick on occasion, he did feel that he couldn't win/was regarded with continual suspicion/was held to higher standards etc.
He's delightful now btw! I think being ghastly is also just part of the 14yo human condition.