Love is blind?

So my boyfriend and I have been together a year now, and have been living together for 10 months. I have a son and he has a daughter. When we first started dating, I was talking to another guy but I ended it when I realized I wanted to get serious with my boyfriend. A month after I ended it, my boyfriend found the texts. He was upset, but we got over it..or so I thought. Now, almost 6months later I opened his facebook for the first time and saw he was messaging at least 5 different girls hitting on them and trying to make lunch plans.. I could tell some had been deleted. He said he left it open on purpose and just wanted me to feel how he felt, and that he was not sorry. Then asked if I had learned MY lesson. The next morning I could not help but look at his phone only to discover that he was still talking to these woman. When I confronted him, he told me that was a test to see if I trusted him or not, and I failed. I just cant help but doubt this is all some plan..even if it is all planned, that is just cruel. He said if I don't trust him we should just break up.. I really don't want to break up, my son calls him daddy. I just don't know how to make him realize HE is in the wrong, and I can't trust him. How do I make him work on building my trust and not just giving up?

If you guys were right for each other and had communication right from the start, there wouldn't be any of the drama that you're experiencing now. You would have established the foundations of trust by being upfront with him about the other guy. At the end of the day, if your bf continues to be in contact with other women, as payback, then you are better off away from him. He needs to get some maturity and I'd be concerned about your son calling him Daddy because he's not much of a role model regardless if he feels he's been hurt by you...and you by him. Ask your bf why he even bothered to set out to undermine your 12 month relationship when it's obvious he didn't trust you in the first place?..