Ahhhhh, adolescence... ...you just have to be consistent, it's like your kids trying a babysitter the first time they keep them to see how far they can go! You also need to make sure that your kids are giving him the same commands that you are. The staring, sounds like a play thing. My 6yr old boxer still does it, and when I don't want to play, I don't look at her, no matter how long she sits in front of me staring. But you must be consistent and patient or yes this will turn into a problem.
Try putting him on a sit/stay when people come in, and the only time he gets love is when he's sitting and still. This will definitely NOT work at first, but keep trying!! Good luck.