My advice to whomever the actual guy in this story is: Get divorced now.

Your "baby" will not be helped by you staying married. When she gets a little older she'll defintely have questions that your wife won't have answers for.

I got divorced when my son was 4 so that he wouldn't have many memories of my life with his mom. If I had been the man then that I am now, I wouldn't have stayed with her more than a few months. But then I wouldn't have my wonderful son.

You have your daughter.

Do you want your daughter to think that mom having "Uncles" over is a normal life? You will definitely NOT be acting the same around your wife and after this. Do you want your daughter to think that is normal?

You should do it for yourself, first and foremost. Did you get married with the understanding that you working a few weeks longer than normal is grounds for adultry? I'm guessing not.

Get. Out.