No choice? We all have choices. In my opinion its worse for a child to grow up in a home around two parents who do not have love for one another than grow up in a stable, secure single-parent environment.
And...eh....maybe you could cheat on a relationship and still make the original relationship work. I don't see how on an emotional level, but that's just me. People work it out every day. And maybe cheating could result in a baby, but the main thing here is if you love someone, you don't marry someone else for any reason.
There are very few personal problems that cannot be solved with a suitable application of high explosives.