Boyfriend cheated

So I've been with my boyfriend for over 2years, I unexpectedly fell pregnant and after much debate decided that i was going to keep the baby - my boyfriend wanted the opposite but eventually we worked it out and decided to make a go of it, i've now found out that in 2012 he apparently cheated on me - problem is i saw this on his facebook messages with one of his closest friends. I feel completely heartbroken, I even remember the date because he had been out that night with this so called friend but was supposed to meet me the next day, this obviously never happened because on this night out is when he slept with this girl, i knew she stayed over at his because he told me that her boyfriend chucked her out (she is an old friend of his) and he took her back to his because she was a drunken mess, he told me he wanted me to hear it from him incase i thought something had happened and I like an idiot thought of how good he was being to his friend, now I know that he slept with her and was just covering his tracks, i don't know whether to confront him about it or move on from it for the sake of our baby girl? Seems from facebook its the only time it has ever happened and he hasn't done anything since, he doesn't know that I know.

Hi I am sorry that this has happened to you. He told you to cover his own ass in case it came up again .....you would not react. It is entirely up to you what you want to do. This is in the past..... but for you it is in the present as you have to deal with it now. Whether you confront him or not this has shocked you and hurt you in the now. It is possible he has not done this since. It is also possible that by you bringing it up will solve nothing.... you will still have to get past this for your baby girl. Do you think you can move on and say nothing? Do you think it will come again in the future ? I would confront him personally it would drive a wedge if I did not say a thing.