That depends on how long you want to support him. I don't know why you paid his rent for a year but, as you have probably realized he is taking advantage of you. My rule with helping my kids is that I will help them when they are doing everything they can for themselves. In other words, if your son had been working and still wasn't making enough money to pay his rent then I would help him. If he is playing video games and spending the money he has on new rims for his car, then I would say stop funding his vacation.