.rowan...there is the world of difference between the attitude to this problem of a man and that of a woman and I can only reply as that of a man.
Infidelity.....first rule is to deny it.........you may have a chance to get away with it, but admitting it right from the start, then one has no chance of getting away with your indiscretion.
When and if the "balloon goes up" there is very little or no difference between being a cheat or being a cheat and a liar..........the end result is the same.