My Situation

I am an uncle to 6 nieces and nephews. I live about 1000 miles away from the rest of my family, so I only see them 2-3 times each year. When it comes time to say goodbye, it is common practice for physical affection to be given out. My siblings and parents will hug each other and me. The children are encouraged to give out hugs and kisses to their grandparents, aunts, uncles, and cousins.

I have two particular problems with this. The first is that the children don't seem to always want to give out hugs and kisses (and I think they should be taught bodily autonomy as early as possible). I know about this question (which I happen to have the accepted answer on) which deals with helping children enforce their own boundaries. For this question I want to focus on the other problem, which is that I don't want the kisses.

I am fine with hugging my nieces and nephews if they want to hug me, but I do not want to kiss them or have them kiss me. The reasons for this are that children give very slobbery kisses (which I don't like) and that none of the adults give kisses to each other, so it seems odd to me that they would have their children do so.

The general conversation will be something like this:

Sibling: Do you have hugs and kisses for uncle Rainbacon?

*Child hides face

Sibling: Come on, give your uncle Rainbacon a hug and a kiss and say goodbye

My Question

How can I decline the kisses without offending my siblings?

When it comes to my own young cousins and children of friends, I usually give them an explicit choice between sharing physical affection and not, while still expecting that they will obey the spirit of the parents request by giving a greeting. My personal script for it is, "Hugs, bye-byes or high fives?" (Basically, give a hug, wave goodbye at each other, or do a high five.) Handshake or fist bump are other options that some kids prefer, so choose the greetings that make sense for you.

I try to include various levels of contact including a no-physical-touch option, so wave hello/goodbye is always one of the choices. My three year old nephew, who is not especially comfortable hugging most of the extended family, really enjoys sharing a fist bump, bonus points for making explosion sounds!

The kids think it's fun, or at least seem enjoy or appreciate that they have a choice. You have control over the options you give, so anything that's out of your comfort zone, like kisses, is already off the table.

I haven't had a parent get offended yet when using this strategy. It frames the desire to share one of the listed forms of affection as your preference, and not an attack on their parenting, so it doesn't seem directly undermining or like you are encouraging the kids to disobey or ignore the parents.

Be proactive and step into the conversation before the parents insist with the child.

The general conversation will be something like this:

Sibling: Do you have hugs and kisses for uncle Rainbacon?

*Child hides face

Sibling: Come on, give your uncle Rainbacon a hug and a kiss and say goodbye

In this scenario, give your Sibling a I can handle this look, or even better, since the problem is recurrent, talk to your sibling beforehand (outside child's hearing).

Sibling, I was thinking since Child is shy around me, when we are saying our goodbyes, could I try something new with Child? Do as you always do and let's see if they will give me a hug spontaneously. Otherwise I think we might want to let Child feel at ease.

Then, when the child starts their shy routine, keep your distance let them get to their safe spot (it might be behind sibling's legs, doesn't matter). Engage and negotiate with the children at eye level. Your objective is to convince the child to give you a proper farewell inside their comfort zone. If the child doesn't want to get physical, that is well within their right.

Mind your body language and voice. Speak in a friendly tone avoiding being either condescending or pushing. The key point here is to make the child feel safe and respected. This will tone down their flight response (they know they can't/shouldn't fight you).

Hey, Child, uncle Rainbacon really loved spending the afternoon with you and it is time to say goodbye. Could I get a (handshake, fistbump, high-five --- or even maybe just either a blown goodbye kiss or a smile and wave from afar) before we go?

My nieces are all shy around people. Their mother tell them to give me a hug and a kiss and they also hide their faces (although I am from a culture where probably these physical interactions are more common - adults do kiss each other's cheeks).

I then negotiate for a high-five, a fist-bump, a smile or just go around the parent they're hiding against to catch their eyes playfully and wave goodbye. Clown up a little. The key is to never force the child into something they feel uncomfortable with but show them that interaction is fun and necessary. They will warm up and overcome their shyness in time, or not.

Respect the child's agency. If they're forced into something undesireable (be it hugs, veggies, or even math), they might develop resistance. Tell them it is okay to refuse contact but that you love them all the same. Reassure them you're not angry at them and whenever they are willing to hug uncle will be there for them.

My eldest niece eventually warmed up and accepted hugs and kisses after she grew old enough. Her behavior helped her sisters to open up.

I have some experience with this, coming from both an affectionate family and a large one. (I have 18 nieces and nephews, 1 great nephew, and several "step" nieces and nephews)

Like you, I'm also against forcing kids to give physical affection. When I run into situations like this, if the kid doesn't want to, I just say "That's cool, how about a fist bump (or high five)?" About 90% of the time, they'll give me a fist bump/high five. If they don't, I just say, "That's ok, love you [name]" and go on about my business.

As for your situation, I would just playfully exaggerate your feelings.

Ew, gross! Kisses!? How about just a hug?

I've done stuff like this in the past, but with kids I'm related to and with kids I'm not technically related to but that I'm close enough friends with their family to be practically an uncle. I don't remember ever getting a negative reaction from the parents.