First of all, he is a married man. Whether or not you are married, this will seldom ever be a winning situation for you. I have heard of so many women having affairs (knowlngly) with married men for years, and still wonder why the guy does not divorce his wife for them...hello...why should he? Not to be crude, but he is getting the best of both worlds. Someone is cleanin and cooking for him; and he gets exciting sex aways from home. Also, in my opinion, a person who cheats on their spouse like that will not make a good spouse for anyone else (I realise that there may be some legitimate reasons for technical adultery--such as being in an abusive relationship with someone who won;t grant you a divorce, etc., and the abused spouse is seeking love elsewhere). I saw this happen in my family. My uncle was cheating with the neighbor;s wife; they both divorced to marry; years later, he was shocked when she cheated on him. Even if someone commits adultery, and the other spouse says they forgive them, and takes them back, you can bet the other spouse will never trust the cheating spouse ever again.
I also agree with what others have said--you don;t even really know this guy (heck, he could be a she for all you know). You say you are happy with your husband, and love him. Are you willing to throw all of that away for this????
My advice: STOP now! Do not let this go any further. The hard part: not renewing the relationship, since it is an online one. It would be sooo easy to do it again, unless everyone changes their email adresses, phone numbers, etc., so you both have absolutely no way to contact each other. This realistically is not gonna happen, so you will need to have self-control.
Also, I would not tell your huuby about it. Just stop it immediately, before it becomes *mental* adultery. If you have any evidence of this relationship, such as printed-out chats or emails, destroy them now.
Put yourself in your hubby;s shoes--imagine how hurt and angry you would be, if the tables were turned.
Also, you should do some deep soul-searching, and ponder why you wish to be involved with another man. What is missing in your marriage, and how can you work with it to make a better marriage?
I hope you don*t think I am being harsh or mean. I am just telling it the way I see it, and truly hope this does help you in some way.