I don't kiss the boys on the mouth. Never really have. Not because I feel any particular way about it but more because of the way other people feel about it. Yes, I realize how silly that is as I write it.
Anyway, in France (sweeping generalization ahead), the vast majority of families don't kiss each other on the mouth, aside from the spouses, obviously. It was never anything I had really thought about until I moved here and French people asked me about it sometimes. Hey, Nicole, do people REALLY kiss other family members on the mouth like they do in American movies?
Kissing here is different, it's true. There's the whole ritual of la bise, you know, the kissing on both cheeks thing. Which is the standard greeting between all children and adults, women with women, women with men, and some men with men, depending on the relationship - family members yes, friends will more likely get a handshake.
At school, most of the children, even the boys who are trying to be very non-nonchalant about their mothers (WHICH INCLUDES BOY1) give one kiss to them when they arrive to pick them up. Despite the fact that this was not necessairly customary for me, when Boy1 told me to 'lay off the love stuff' when I picked him up from school (and by that he meant hugs), I decided it was better than nothing. So now I get a polite peck on the cheek. Thankfully, Boy2 is still young enough to care more about getting a hug from me than being cool while his friends are around.
Back to the kissing on the mouth thing. It's generally, even by children, considered to be a kiss reserved for people in a romantic relationship. Once, Boy2 turned his head as I was giving him a kiss on the cheek and he laughed and said, "Ooohhh, we kissed on the mouth."
So, the other day Boy2 actually asked me if we could kiss on the mouth. I said no, some families, mostly in other countries, kiss each other on the mouth but that we weren't that kind of family. His reply, "Let's be that kind of family." I said no again. His last attempt, "How about we let eeny, meeny, miny, moe decide?"