I'm upset with my dad for kissing my baby
Why are you angry he kissed your pet?
It's not my pet, it's my kid! Ewww, don't do that to kids
Sorry, I thought that you were referring to your pet as a baby, as some people do.  Kissing a baby is not a big deal, you shouldn't get upset at parents for displays of affection. If you do have any objection, though, you should ask them beforehand not to kiss your baby.
He should have asked me first! My kid is precious so everyone should keep away from it.
I can understand why you want to keep your baby safe, even from family members, at a time like this.  However, interacting with the world is how children grow and develop their resilience and their immune systems.  Since your baby is part of the extended family, you should allow close family to show their affection.