Is this sexist or just pride?

I was walking with my boyfriend through town today and I mentioned something about going to see Vampires Suck on friday and he said he didn’t think he could go because he’s broke so when I said I was planning on paying for him he got all upset and we got into this whole conversation about how he would feel bad if I pay for him because he’s the guy and I’m the girl and HE’S supposed to pay for ME not the other way around. If this is just pride then will someone please explain to me why he’s like that and if it’s sexist I need to know so I can punch him in the face. Thanks!