Can a man sleep with only 1 woman in his life? Relationship insecurities.?

[......]

I have been with my boyfriend for 2 years, we got together when he was 19 and I was 21. He is just under 2 years younger than me. I found out that he hadn't done anything at all with any other girl but didn't really think it would get serious as I'd just had my heart broken by my fiance who decided he had more to do before settling down (he'd been with hundreds of girls and done everything and is married now).

2 years later and I love him with all my heart and I feel like, by being with him, I'm setting myself up for heartbreak because I feel as if I'm in a relationship that will inevitably end because he'll want to experience things before settling down.

People crave variety naturally and even if he did stay, wouldn't that always be on his mind, even if he's lovely (which he is) and loves me, wouldn't he always be trying to vent those frustrations through the porn he watches (watching porn is fine by me) and the women he thinks about and the fantasies he has? Wouldn't he resent me?

I recently discovered he follows a girl on twitter who just randomly takes pictures of her huge DD breasts and he sits there clicking through them etc and while that's very insignificant generally, I'm flat chested, he's never had another girlfriend, so isn't that just another thing he hasn't experienced...boobs lol Its ridiculous.
It's like me being with one man, with an extremely small penis, while in the scheme of things that's not what a relationship or love is based on, wouldn't it always be 'what if'?

I know that no-one here can tell me what will happen or change the situation but I need advice and opinions and others experiences. If its scaring me so much and Im going to be hurt, am I better off just being straight with him and telling him to go live his life?
How do I discuss my fears with him in the best way?

[Angela]

you have been together for quite a long time. if you are really worrying about this then you should probably ask him about it. not all guys are the same and sometimes they find someone straight away who they want to be with. not everyone sees what you described as experiencing life as experiencing life.