As a mom I pat her butt I kiss her butt (over the diaper and pants) squish her little cheeks. But I’m also her mom and I bathe her and she came out of me. My husband and everyone else is only allowed to touch butt during diaper changes and when she is going to sleep she likes a butt pat while being rocked. But there are only 3 people that put her down for naps.
Regardless of its normalcy, if you're uncomfortable you should set boundaries.
I do that to my daughter all the time
It IS a normal thing, but that doesn’t negate your comfort level with it. If it’s uncomfortable for you, definitely speak up about it 🥰
My baby loved it when he was itty bitty and he still does. It seems to calm them down
If you don’t feel comfortable with something let them know you are the mom and you put the rules no matter what they say or who they are trust me you will feel better
It's normal. I'm sure your dad did that to you as a baby. Don't worry. He's not being weird.