This is a tough situation. It sounds like your son has found that he does get a lot of attention from this behavior, even if it's negative attention, so he continues. The way he smiles and says he loves you could indicate that he somehow understands the buttons he's pushing in you. What I would do (and I'm sure many would disagree) is immeditely remove him from the situation when he acts this way, without getting angry or yelling or having a strong reaction (which he seems to love getting from you). Have a place you can put him, where there's nothing to play with or look at, and walk away. When he comes looking for you, put him back and walk away - no reaction. Do explain that this behavior is not okay and won't be tolerated, matter of factly, without yelling. Stay strong and be consistent - even when others are around.
Also, be sure you praise him when he's playing nicely and doing what he's supposed to. If you lavish him with attention for being good, he'll find less need for being bad.
I would also insist that the doctor run some tests to determine if he has an chemical imbalances or impulse control issues. If your doctor is unable or unwilling to do so, I'd find a doctor who is. This truly could be something your son cannot control on his own.
Good luck!
D.