Hey Tim,
Long time no see dude. Well, it looks like Mr. Happy got you in a pickle again, just like it does for millions of other guys. No matter what happens in this situation, there is going to be pain my friend, and you have to face up to the fact that you contributed to it. I know you have moral character and that you will end this relationship honestly and tell her that you are sorry but you phucked up big time. I'm not going to get on your case and try to make you feel worse than you already are. I do hope though that this helps you and any other single guys out there to think before you get sexually involved with someone and TELL them that you want an OPEN relationship. Hey, this doesn't kill your chances of getting laid, believe me lots of women not only tolerate but enjoy open relationships these days. Never use someone without it being mutually agreed upon for sex or you will hate yourself for it later. If you can't follow these simple rules, you just need to lay down $6,000 and buy one of those android sex dolls to do. At least they don't have pain receptors built in them yet.
Skipper (kicking Tim in the butt)