My current DP I trust implicitly. Girls check him out when we're in town and I have to admit that if I've had a few drinks, I "mark my territory" by going up and giving him a kiss or something, but usually I just laugh, because I know that no matter how hard they try, he's coming home with me. I also know that he thinks that I'm "the one" and his future, and he would do nothing to jeopardise that - plus he's far more interested in working on his midget. He does look, and I'm fine with that cos heck, I look too, just a little more discreetly LOL At the end of the day however, we love ach other, we want a future together, and much as I or he look, we are happy with eating at home
My ex is a different story. He had a history of cheating, on every girl he was with, and made no secret of it, and (he was honest I'll give him that) he made it quite clear he would cheat rather than end a relationship that wasn't going to plan. He looked too, but on a far greater basis than I would class as "acceptable" (i.e. I was embarrassed by it, and he knew it, because it made me feel like I was just something he was passing time with until he found something/someone better). Add that to the fact he registered on dating websites (I found out after we had broken up) while we were together, and I guess my trust issues were real.