It felt like I was looking into the future when I read your post. My W and I have been separated for 3 months, and already I can see how my W is filled with so much self-hatred and guilt that I don't know if she'll be able to forgive herself and come back to our M.
As for your sitch, you have to get her to agree to no contact and total transparency with OM. Until she does that, it's going to be incredibly difficult for you to start piecing your M back together, if not impossible. She needs to decide what's more important: Her M or her "friendship" with OM. If she picks the OM, then if I were you I'd go dark again.
And while she may not have had intercourse with the OM on V-day, I guarantee you that there was some inappropriate sexual conduct. She's not over him. And the only way she will be is if she cuts off ALL contact with him and goes through withdraw. Right now you're still competing with this guy for her love and attention, and that's a competition that no married man or woman should have to take part in.
I agree with ALL of this, esp. the Valentine's Day part. Wayward, fogged-out spouses will ALWAYS lie, and usually when they cop to something, it's one (or even two) notches LESS than what really happened.
Bariga, I think she's playing you. I think your coming back to care for her was honorable, and I commend you. But I think you need to chalk it up to "I did it because it was the RIGHT thing to do," and not suppose that it scored you any points to win your wife back.