Kissing family

Is it weird that I'm annoyed/grossed out that my boyfriend (who barely kisses me and is mostly pecks) kisses his grandmother on the lips and I think I've since him kiss his cousin On The Lips, pretty much the same way he kisses me? Because I'm upset.

(He doesn't like kissing. He said he hasn't in any of his relationships. It sucks but it's not a deal breaker. No need to be rude)