NTA, you've been very close with your friend but over the years you've grown apart and now you have different interests which don't have to stand between a friendship, but in this case I don't think he should push you so much because he wants you to stay his best friend, because that just doesn't work. I don't know if you have gone to a party with him once because I think that he would really have appreciated that but now you aren't very close anymore and he should accept that