This brother is one piece of character! Its not a personal decision to reject visiting a party! Allah(swt) forbids us Moslims to make any contribution to a something, situation what gas not HIS approval! The presence of someone is a contribution to make the party more “successful” in the eyes of host and guests. In case of Khabib as guest then contribution of success is guaranteed! Moslims doesnt go to places where our prophet Muhammed(pbuh) wouldnt like, Moslims wouldnt do or accept things what Allah(swt) or his Resul accept. This is the way we should live.