So, this is my first post and I'm not quite sure what to expect.
I don't really want to ask anyone I know in RL about this so I thought I would seek the wisdom of strangers.
Basically, OH and I have been together for 13 years and there was quite a few instances when we first met that OH would get drunk and be very, very flirtatious with other people (one friend even asked if we'd broken up as OH was being quite full on).
On one occasion on a night out(which was the last straw for me) OH flirted quite openly with a friend of a friend whilst I was stood there. This was bad enough, but it followed a day of flirting with the same person - really trying to get their attention, etc.
We got into a heated row about this and I was made to feel that I was imagining things. Well, fast forward to the present and during a recent difficult patch between us I asked for the truth about a few things and it turns out that I was right - OH admitted that they found the other person more attractive (at the time), and the flirtation was deliberate to "feel better about myself". OH also admitted that if I wasn't there they probably would have cheated (kissed).
I know this was ages ago - but I feel pretty gutted about the whole thing. Especially as this was not an isolated incident (though it was by far the worst). OH has never actually cheated, and I know that I'm probably being overly sensitive - but like I said I'm gutted.