I was brought up with very little, and sometimes no physical interaction. When I became a Mother, I showered my Kids with affection. My Daughter is very affectionate, and gives little pecks on the lips, but my Son grew out of that by about age 6. He's a hugger though.
I can totally relate. I've always had a very close relationship with my parents and my brother. Growing up, we weren't a very affectionate family but we all always knew the love was there. We've all been through a lot in life and we've always been there for one another. For some reason though, I turned out to be very affectionate toward my son. I probably hug and kiss him 25 times a day. I sometimes peck him on the lips but more often on his cheek, forehead or on the top of his head. I don't see anything wrong with kissing family members on the lips but for me, the only people I kiss on the lips are my hubby and my son (and I'm sure that'll change as he gets older. At 4, Mommy & Daddy are still his world!).