That is exactly the type of thing that makes a young person end up in jail. If he does that when he's an adult, he will go straight to prison, as well as fvck up a lot of other chances that he might have in life. There's a lot of jobs that involve handling money, from bank teller to CPA, stock broker, or lawyer. And he'll never get one of those jobs if he was ever caught stealing.
But at the same time, you don't want him to feel like you only care about him when he behaves well. It's easy for a kid to confuse "you fvcked up" with "I don't love you any more." I don't think you can treat him like a woman and just withdraw your attention, because I'm not sure he'll see that it's done out of love.
There is a famous quote from George Washington, where he derides much of the continental army as being "summer soldiers and sunshine patriots." If you only want to be around the kid when it's fun, then you're a "sunshine patriot" in the kid's life, and he will see right through it. If you love someone, then you are with them through the good and the bad, which is what you have to teach him.
Not that I am any parenting expert, but I would say to bring him over for the weekend like you normally do, but then ground him. Make him do yard work or something not fun, but be there with him the entire time. Show him that he is worth more to you than having a fun time for yourself.
