NC, and really at a loss! Will keep brief as would rather not be known in RL.
I very strongly suspect that my friends DH and our mutual friend are having an affair. Very randomly I was out for dinner with work people and saw them there together. They were being very couply and cosy, holding hands, kissing, giggling until they saw me, I was really shocked but they then shortly got up and left, they didn't talk to me at all or really acknowledge my presence, but they definately saw me. Friends DH had told her he was working away that night. They know I know but haven't said anything to me, this was last thursday night. It does make sense to me as a few months ago I commented to my DH that I would be uncomfortable with him being as friendly and flirty as friends DH was with OW. Friend has also commented that mutual friend(OW) hangs around alot... but it has never gone further than that. DH thinks I should leave it, he says that they know I know so that will either prompt them to come clean or end it and I would be better off not being involved.
Do I tell friend? WWYD?