as I am sitting here reading your question...the only two things that comes to mind are this...
first...some fact... you are so caught up in men being faithful...when reality is..now a days...women cheat just as much as men...there are plenty of recent studies to prove this. now ten fifteen years ago this was not the case...men were I believe 40 percent more like to cheat then women...but that is just not the case anymore...women have very much evened the playing field. so even though at one point in time it was fair to have this very one sided view of cheating...it is not anymore. both men and women do it almost as much as each other.
second..and more importantly...
you have some sort of insecurity about being cheated on...why that is I don't know...what I do know is that you need to work it out... bringing this type of insecurity to a relationship...especially without cause...will inevitably be the downfall of you two... men and women alike can pick up on their partners insecurities...so when you are constantly worrying about him cheating ...he can sense that ... he can feel it...and it feels like distrust. now when you are giving someone energy of distrust for no reason...there natural reaction is to feel attacked...and rightfully so because you have a lack of trust for them that is undeserving...as he hasn't done anything to embed this idea of cheating into your brain.
thus the stepping stones for many future problems and insecurities and trust issues are layed...eventually splitting you two apart.
do men cheat? yes
do women cheat? yes
are men faithful? yes
are women faithful? yes
it is really an even playing field...so my advice to you ...is to start working on this insecurity of yours...figure out why it is there ...and work on it till it is gone...before it starts to put an unnecessary strain on your relationship.
hope this was helpful
Brian from www.ideabombs.com link