its hard to be so many miles away but if you have these thoughts now act on them, take time away from each other and wait for her to reply first , then if she does tell her your thoughts and be truefull, reading what you have said you are saying this man and your partner went away and he either had sex or tried too, you must ask her this only to clear your head, good luck, but remember there are lots of other people that are waiting for someone to love who ever they are