People do to you what you let them do to you, remember that. If you are going out of your way to spend time with him when you have a sea of other options available and your free time matters too, don't keep putting up with that. My suggestion is don't spend as much time together so that when you are actually hanging out, it won't be so taken for granted and abused. If he wants to play on his computer, he can play by himself. There's a time and place for electronics and a time and place for you. Unless he's including you and you are both doing something together on the computer, don't put up with it. Let him know that your time is valuable and that if he's going to stay on the computer, you are going to leave. Go do something else, it's your time, too.