Bob,
Thanks for sharing your story.
It sounds like you had an interest/sexual attraction to men that you felt unable to fulfill so you resorted to online hook-ups with me and though it started out as a playful way to "have your cake (marriage) and eat it too (be with men)" it ended with multiple parties being affected by your actions. This is the unfortunate reality of men who act on the down low.
Your wife, I am sure, is devastated - her husband is presumably homosexual afterall. That is not an easy thing to deal with for her (or you), but you should let HER decide what course of action she is comfortable with taking. After all, she is the one who got cheated on. The one thing you can afford to do for her now is to be honest with her about your hopes, dreams, desires, attractions, etc. Don't hurt her anymore than you already have. This is your chance to be a man, so be a man.
As for your lover: as a gay man who once got involved via internet with a "bisexual" married man, I can tell you that your lover is probably just as devastated as your wife (if he had feelings for you). It is a difficult thing for the lover to have that connection with the married partner and yet the married partner can not pursue those feelings - it results in the lover feeling used, betrayed, and made a fool of.
If I may offer advice/insight? It's tough love, and a bit of a reality check that you may not want to hear.
Fact: You are attracted to men.
Fact: You cheated on your wife with a man.
Fact: You developed relationship-like felings for this man.
Also fact: Many more children nowadays are growing up with blended families, same-sex parents, etc. Your children will likely grow up to become well-adjusted, tolerant, accepting, loving people - so long as you establish those qualities through your Actions, with a capital A.
Fact: Many men who divorce because they are more interested in a same-sex relationship continue to have healthy contact with their former wives.
Life is too short to go around hurting people (your wife, your lover, yourself!).
Again, you are taking a big step by reaching out (even if it is on a forum) to get advice, share your story, and feel more comfortable with you are. Congratulations on that!
Best of luck and remember, actions speak louder than words.