NUdging to get them to clamp down harder usually works. I do that with mine when on occasion they don't quite have them constricted enough.
It doesn't bother me, since if I were to feed f/t I'm still responsible for that rat's death too. It's just more honest this way.
The little male might have also been food-fixated and your hand is hot. That's a target at that point to him. It's great that he's going after his food.
If buying jumbo mice is more expensive, think about going to a small size rat, like a hopper/crawler or whichever is the same size as a jumbo mouse. That will get him onto rats, so as he grows you can up the prey size still, and avoid having to buy multiple mice for one snake.
Sounds like you've got some good eaters there! COngrats!
(BTW I like rats as pets too, they are great!)
Wolfy