How do you tell relatives to not force affection?

I'm teaching my daughter about having agency over her own body and would like to know what words I should say, how to express it, to let relatives know that they should back off when they keep asking for kisses from my daughter and hugs when she is clearly uncomfortable, or even that they shouldn't be asking that of her at all regardless, because it sends her the message that she needs to hug and kiss people to please them?

Also, what do you do when you overhear someone saying "ssh, don't tell mommy..." about something to your little one, (like maybe giving her food or something?)