Well, I’m an outlier here. My family (extended both sides, so cousins, Uncles, Aunts, etc.) never kissed their kids on the lips, at least that I saw. It seems weird to me, but thats not unusual considering it wasn’t my experience growing up. Only person I kiss on the lips is my S.O. (And I don’t ever see myself kissing my kids on the lips.)
Edit : Of course, kissing on the cheek happened…just the lips part didn’t.
In my experience/custom, kissing on lips is reserved for romantic partners.
Ha ha ha! Exactly. There is no other appropriate response to such foolishness.
I’m not sure exactly how I’d react if I saw someone kiss a member of their own family on the lips, but I can’t imagine I would ever talk to them again. I’d just be… yikes.
My dad is getting more gooey(?) as he gets older and he’ll kiss me on the lips from time to time when saying goodbye. He’s pushy about hugs too.
I think he’s sort of depressed. It’s the least I can do.
I’m 44, and my dad and bachelor uncles do this to me. I thought it was normal until I grew up and went out into the world, and subsequently changed my mind. But even as I go in for a bit of cheek, they go in for a bit of lip.
I love them too much to tell them it’s a bit squicky. There is no stopping them. I do enjoy telling my friends and grossing them out, though.
We have no choice in the matter, my little girl will always kiss me on the lips, she will always grab her Mum’s face and kiss her on the cheek. I leave the complaining to her Mum 
I’m not about the lip kissing with Celtling. I’m sure it’s normal and fine in many families, though. I have never kissed a family member on the lips,a nd I’m sure they’d be grossed out if I did.
It was not a big deal at all in my family, though as others have said, it pretty much stopped by age 10 or 12. We used to do three-way kisses a lot.
It was a little weird a couple of years ago when my 50-year-old brother came into town and greeted me with a smack on the lips. Ew, gay incest!
With almost every woman I’ve dated in the past 20 years, I would customarily greet their mothers with a hug. Maybe a cheek kiss, but probably not. But there was one mom I met for the first time, and for some reason I kissed her on the mouth. In front of her husband, no less. And every time I saw her after that, I figured (for some reason) to do any less would be an insult. So I kissed her every time I saw her.
I leave it up to the kids to decide. My youngest sister won’t do it when she goes to give me a kiss, but my nieces do. Two of my best friend’s little boys go for the cheek, but her youngest goes for the lips on anyone he tries to kiss. There’s nothing romantic or sexual about it, it’s just a young one trying to show affection, much like a puppy licking your nose, face, hand, etc.
I’m 29 and I still kiss both of my parents and my mom’s dad on the lips. What’s the big deal? If someone has a problem with that because they think there’s something incestuous about it, well, I can hardly imagine anything that would be worth less of my worry.
When I graduated basic training 8+ years ago and we were getting our pre-graduation briefing, the squadron’s XO was explaining the rules about PDAs mostly for the benefit of those Airmen who were going to be seeing their girlfriends or boyfriends for the first time in two months, and I naively asked whether it would be OK for me to kiss Dad. I got several “Aww’s” from the females in our sister squadron; my XO just laughed and said it would be OK.
I agree with Mr. Accident. I would leave it up to the kids to decide. When I was young I kissed my mom on the lips and stopped and started kissing her on the cheek and forehead when I was about a preteen. It just naturally started fading. Sometimes when I kiss her now, I aim for the cheek and sometimes hit her lips instead. But it’s not weird. It’s just different and we usually have a laugh about it.
My 5 year old sister kisses my mom on the lips. I try kissing her on the cheek but she always goes for my lips. It only grosses me out because my sister gets messy and gives sloppy wet lipped kisses.
Kissing like that is not perverted or weird at all, its just like the OP said.
So…some posters whose parents kissed them on the lips, and hung around them naked. Some of you all have really different families than mine.
Another vote for A-ok to kissing elementary age (and younger) kids, on the lips.
Brilliant! We should take it further… we all know that kids are at most risk from their families and friends of the family, so we should take all kids at birth and give them to strangers to raise… hmmm… I may not have thought my cunning plan all the way through. 
I’d also like to echo the “FFS”.
My FIL kisses his sons and his DILs on the lips. It’s just the way he is and there’s absolutely nothing creepy about him. If someone is so sick as to think there’s something wrong with that, they’ve got the problem, IMHO.
My first impulse was to answer, “They shouldn’t *not *kiss their kids on the lips.” What I was thinking was that when they’re smushy babies and everything about them is so well, kissable I have no problem with parents kissing kids on the lips in any combination of genders. As they get older that falls away.
Once in a while my son or I will misjudge angles and we’ll graze lip to lip on the way to an on the cheek goodnight kiss. It’s not an occasion to freak out.
Huh. I honestly even find the idea of even cheek kisses to be odd. Hugs, sure. Cuddles, maybe forehead kisses when you are sick, stuff like that is fine. But cheek kisses are something a girl does to a guy as a reward (while lip kisses mean they actually like them.) I would be weird coming from family.
Mine as well.
I wouldn’t try and stop other people from doing it, but I’ve never kissed any of my relatives on the lips.
If both parties are comfortable with it, no big deal.