Does the little green monster really truly exist?

So I find my self (finally) in the situation where I'm dating someone... at least i think so. We haven't really had the discussion as to whether or not we're just friends or we're dating, and we certainly haven't gone as far as having the talk of exclusivity. We've been seeing each other for about a month and he seems to be pretty secretive about his life. I try to tell him as much about my life as he wants to know, but I don't know much about his beyond his likes and dislikes or where he works.

Now like I said, it's only been about a month, and we don't see each other during the week because of my work schedule. But that fact aside, i spend every weekend at his house. We sleep in the same bed, we cuddle, we kiss and all seems well.. but so far, he has dodged every sexual advance I have made with the exception of one, which went unreciprocated. I finally got him to reveal that last night he just wasn't in the mood... this leads me to believe that he is just not that sexual of a person... fine... but then explain to me the greasy handprints on your headboard... there are two of them and these hands are much smaller than your own. All signs point to him having somebody else over in that bed, and I don't think they were just cuddling... so why is he doing these things with somebody else when I have been trying like hell to get him to do them with me? I don't know... but it seems to make me jealous that he is sharing one of the 2 biggest things I want from him with somebody else.

Now all that being said, we haven't had the talk of whether or not we're just friends or dating, or what we are for that matter. And there has not been any talk of exclusivity or anything, so I really don't know what to think... I just know what I feel and I feel that he is hiding that part of his life from me becase he would much rather be sharing it with someone else.

Call me crazy!! LOL... I'm just really insecure about relationships having been completely non-stop single for over 3 years (more like 5ish). I tend to question everything when it involves somebody i'm possibly dating. I question why they aren't as open about stuff as I am, I question why they didn't want to hang out last weekend... but some things set off more than red flags than others, and I think that's why I'm feeling even more apprehensive about persuing this relationship any further. I know that my mind could be put at ease simply by talking to him about it... but some people are extremely put off by those conversations especially so early in the relationship and I'd be way too afraid to screw things up, especially if he felt they were going well.

But like I said..once again, we've only been "dating" a month or so... so who knows where this is going to go... I guess only time will tell. Part of life is the experience. We revel in the good ones, and learn from the bad ones, so I'll take whatever I get.

Remember what doesn't kill you, makes you stronger.

BTW, please use the comments section. I would like as much advice as I can get. Thanks all!

~S~