He is rather gorgeous!
The youngest of our brood of five, male neutered, likes to show his dominance with a much older, neutered, female. She goes along with him until she smacks him one.
Another of our males will sit on toys, or cats, to prove dominance. There are lots of objections to this behaviour by the others!
Your boy looks like a fine healthy fella. Your vet will put your mind at ease but I wouldn’t be too concerned.