How do you find out if your boyfriend is cheating on you?
Little Miss Berlin answers it for you:
with my first serious relationship, i was so completely able to trust my boyfriend that it was a shock to start dating again and realise that most men had wandering eyes..even when i was with them, so who knows what other part of their body was wondering when i wasn't with them. there hasn't been a single guy since who i felt i could completely trust not to cheat on me and that is without even having been cheated on (to my knowledge).
this, i believe, is particularly as a result of living in fast-paced 'single cities' where everyone is there 'for a good time, not a long time'. men and women alike, are out so frequently and meeting new people so often, that the guy you exchanged numbers with on tuesday is forgotten by thursday. that's if you even remembered what name you saved the guy from tuesday in your phone as by wednesday morning. (try the name of the bar you were at!) but maybe it's the same wherever you live because it's not human nature to be attracted to more than one person at a time. that doesn't mean everyone acts on the attraction though.
if you are so concerned about it:
a) you're paranoid and have trust issues that have something to do with your father and/or having been cheated on before.
b) he is. just straight up ask him when he's not expecting it. his reaction will be telling when caught off-guard (unless he's an actor. or a musician, but only a front man, bass players permanently seem unnerved. that's their charm. and if you've got a bass player, they're not the cheating types. unless it's a band where the bass player is also the front man, in which case you should consider the guitarist).
c) if he is, he will slip up soon enough. and then you will be out of this misery of doubting him and doubting yourself and can start to move on. but don't rush and remind yourself that they're not all like this (i have at least two male friends who are really decent). a friend told me that his dad's advice was, 'Get everything out of your system while you can so that when the right girl does came along, you're completely hers'. Many decades later, the advice giver in this story - a ladies man in his youth - is still happily married to the 'right girl' who came along in the midst of all the other ones.
that story gave me hope. i hope it gives you some too, if not about your current boyfriend, about the next one (and even more so if you find yourself with a guy that has been around a bit. see it as a positive, not a negative!).