Hi and welcome to YT. Buster has a snuggle puppy toy that we call Bebe. She is his best girl.
After he is done he always kisses her ear.
I really don't mind and feel it is a natural release of energy. Everyone needs to feel dominate sometimes especially if you are so small. If he was humping my leg I would not allow that because that would be dominance over me and Mommy is the boss.
If you are uncomfortable then I agree with Wylie's mom about getting rid of the specific toy or washing it.