I've always kissed my parents for hellos, goodbyes, goodnights, happy birthdays, merry christmases, all kinds of stuff. It's a greeting, and an expression of love (non-romantic of course!). But I've met some people who are weirded out when they see me kiss my mom or dad hello/goodbye, because they see kissing as nearly exclusively romantic or sexual. I guess it's a cultural thing for some, and a lot of it is based on what your own parents did when they were kids. Either way, I'm curious!