Bipolar Disorder Support Group
Bipolar disorder is not just a single disorder, but a category of mood disorders marked by periods of abnormally high energy and euphoria, often accompanied by bouts of clinical depression. This is the place to talk about your experience with bipolar disorder, learn from others' experiences, and find support.
He's just coming over to put on the air that you have a "relationship" probably to his friends. You are near and in person in case he gets horny.
Set up a trap if you really need to get it set in your mind. You said you signed up on the site and contacted him. Go back and see if he will meet you somewhere in person. If he says yes then in person you make an excuse why you can't see him that night. That gets him off the hook of having to come over and he's free to meet your on-line person. Then go and meet him make it at a restaurant or bar/club. Sit where he won't see you then send him a drink and say it's from your screen name and have them tell him where you are sitting. When he comes looking for you. BUSTED!!!
But I think you already know that he's not the guy for you. Or you wouldn't be asking us our opinion.
It does sound like something is up. Hopefully he'll be honest with you when you confront him.