My boyfriend is a pathological lover

My boyfriend and I met through a friend. I thought he was gay. We hung out for a couple of days. Pretty much from the get-go, he was all 'I love you, I love you'. Well, we started dating exclusively. After, like, 2 weeks, he's all 'im going to marry you'...blah blah blah. Well, we've been together for a while and I've started finding out about his past relationships. They all go just like ours. 'I love you's' from day one. How am I supposed to trust that he is being real, and just not a girly man(he's 36 years old). Is he just in love with love or could it all be a game?! Help!
To clarify, this guy and I are living together now, and the whole gay thing isn't an issue at this point. What bugs me is that it seems in all his previous relationships, after like, the first time he and someone would hook up, he would start with 'I miss yous' and 'I love yous'. I just think that he might desperately be looking for someone to be with....I don't know. Knowing that he has told every girl the same thing he tells me makes me feel average...and I know I'm not. I just don't want to be yanked around

Unlike women guys have several different I love you's. The first being they use it because it gets them what they want. It also is great when they do something stupid and they need to get back into your good graces. Be aware of this. Men also say I love you to women they think could be the one. Have you ever heard of a guy saying "I love you, but I'm not in love with you?" This is a guys way of saying you could be the one but your not it right now. All my serious boyfriend's have always been the first ones to tell me they love me. It a kinda tool for them, it doesn't mean that they don't mean it but that there definition varies from ours. When we say I love you we mean it as a sign of deep everlasting affection. Men think thats what women want to hear, even though it probably scares us off more than it works. It isn't nessarily your guys playing games or is a cassanova.

Work on your friendship first. If he turns out to be gay you got a friend for life. It could be that he IS gay and doesnt even realize it, reason for which he bumps from girl to girl looking for Mr. Right in the wront places.