How do you kiss someone without them knowing?

Then don’t kiss them.

If you are not pretty sure that their reaction will be positive, don’t do it.

Blow them (the kiss).

You could try the Cosby-Method™.

Trademark! Terrible.

If you are not sure if someone wants to be kissed by you, don’t do it, unless you ask them first. If they say no. Do not try to kiss them.

Better not.

If you don’t kiss them now, you can still do it later—if you’re sure that kind of attention will be welcome. But if you do kiss them, you can’t un-kiss them. And you might wish you could.

And—are you really thinking of kissing someone who won’t even realize they’ve been kissed? Are they in a coma or what? That seems like a poor bet to me in any case.

I was once in a similar situation. I bought a bag of the chocolate kisses. I told him, “I want to give you kisses, then before he could respond, I took his hand and filled it with the candies. He smiled.”

You don’t. The term for that is assault.

While they’re sleeping?

Tell them you want to kiss them. If they are cool with it, then have at it. If they don’t want to kiss, don’t be a creeper, respect their desires. Or lack thereof.