Well, initially, what made me stay was:
In the beginning part of me stuck around because I wanted to make sure the OW didn’t get my h.
Unbeknownst to me, FWH dumped OW (they were shacking up in a trailer in a "friend's" driveway) and explained to her that he had to "try to win Want2help back". According to him (and other people have corroborated) she cried and begged and pleaded then told him I wouldn't take him back).
We didn't find out she was pregnant until 1 month into R. 1 month of IC (for both of us), MC, committing ourselves to one another. During that R I got 100% remorse, transparency, promises that he would spend "every day for the rest of his life making up for the hurt he had caused me" (his words). Really the ideal remorseful spouse.
Upon the OC dday, I threw him out. I was on the phone to my aunt (the only person I told aside form a friend who was by my side when OW and my stepD called to tell me OW was pregnant/gloat over OW's pregnancy/giggle like catty little bitches). My aunt asked "If she hadn't come forward as pregnant, would you still want to be with him?"
"Yes."
"So, are you going to give up, and let her get her way?"
(When OW showed up at FWH's place of work to announce her pregnancy, thinking FWH would leave me and pledge his love to her then and there, he told her he wanted nothing to do with her. She was yelling "Let's see if WANT2HELP wants you NOW! I can't wait til you tell WANT2HELP, I want to see the look on her face! Let's see if Want2help still luuuuvs you now!")
"No!"
No, I decided not throw away the 6 years and everything we had been through (raising his kids, my father's death, raising my brother together, etc.) for this whore and her baby.
Now, that's not to say that I never felt like I had made a grievous mistake the day I decided to stick it out, I have, particularly when OW was flaunting her pregnancy, then the "Help Baby" (she made multiple social networking profiles for newborn OC using our last name ("THE Help Baby") and sent them to every one of my friends and family, with pictures of FWH labeled "sperm donor").
I still feel like that some days, although they are FEW and far between. Recently we are sinking more and more money into a lawyer for OC's adoption. We may have to hire an attorney FOR OW and her H, as our own attorney is fucking everything up. We're both students. This money is incredibly hard to come by, and we keep sinking money into OC (not to mention back child support that is racking up until FWH is out of school). All of this money is being diverted away from MY fund for my internship in another country, where I hope to one day live, and is pretty essential to my education. So, yeah, we have our bad days.
I guess what I'm saying, is you have to decide if your M, and more importantly, your H, is worth it... and that criteria is different for everyone.