I think he's got a girlfriend?

Me and this dude have been "seeing" each other for about a week!! The other day he called me "kerrie"... i brushed it off but i was nosing on myspace and I came across someone called kerry and in her name she had his name and paragraphs saying how much he loved her and how happy they were!!! there were comments from his friends about 3weeks olld... also on one comment she said that she was going over to his etc... i asked him when he finished with her and he said about 2months ago... =| ... should i ask him or would i look like some crazed stalker if i'm wrong? Helpp =)