Keepsmiling, sorry I usually do not like to respond to these type of questions, as generally I tend to be a bit more "tough love ish". I believe in STANDING, but I do not believe in letting ANYBODY cake eat. We have to protect ourselves and prevent our spouses from exposing us to dangers such as STD's, and emotional pain. WE have to remove ourselves from their drama as soon as we are able. That means, if it HURTS him too much to stop seeing other woman, then it is time to see how much he will HURT if he does not have YOU.
I would never suggest asking him to leave or anything drastic. You must ONLY ever do what you know you can LIVE WITH. Always be aware that for every action there is a reaction, which means unless you are prepared to live with the consequences do not do it. If you are, then proceed.
Most of us in the early days, (3-6 mos.) are incapable of doing much besides cry. Once we get past that stage, we learn fairly quickly what we can and cannot tolerate or condone. For me, I was not going to share my h with ANOTHER Woman.
The rule of thumb (this is not cast in cement, nothing is honey), do not make ULTIMATUMS you can not or will not go through with. The belief that there is ONLY one chance at a first impression, or impressing on your spouse that you mean, is a myth. That being said, the more times you back down from a threat or a promise for that matter, the less RELIABLE/ believable you are.
Do what you THINK is best for you! Like dealing with a child, mean what you say and don't say it, if you don't mean it.
Hugs Stayed...