I'm not sure where to post this. Have been with my OH for 8 years, due to marry later this year. Around 18 months into the relationship I found out that he'd been seeing someone else briefly. I was devastated, he moved out for a time but ultimately we worked things out. We now have two children, upcoming wedding and are really happy and strong.
During the time we were apart, I very foolishly had a one night stand with one of his friends. Very stupid, but at the time it didn't come out and there has never really been a time to bring it up. Said "friend" has since married but is now getting divorced. We haven't spoken in about 5 years as he and DP fell out over something unrelated.
Last night I received an email from him, containing a picture he obviously took on the night in question, with the caption "your life is about to be over". I didn't know this picture existed; it was taken without my consent but is clearly me. The email didn't say anything else. Today I've had three voicemails from a withheld number, two just silence and one which I'm assuming is him saying that my OH will soon know what a cheating slut I am as he can't let us marry without the truth being out there. I have no idea what to do - OH and I are in such a good place so this will taint everything, particularly with the wedding so close. I have no idea why he would do this, but it sounds as if he's going to make it out to be an affair rather than the one night it actually was. I know it's partly my fault for not being honest but this has the potential to ruin everything. I don't know what to do.