Husband won't come clean.

My husband and I have been married for over a year. Around November I noticed another women he was texting in his phone inappropriately. He said they were just friends and I let it go. In December, same thing happened and I let it go. Both times I was convinced he was lying but I didn't have enough evidence to know for sure. In March I found out he was seeing another women for about 5 months and this time I has solid proof. She said everything and pretty much she was frustrated about being the "other woman" for so long. I even saw a picture she sent to him. I confront him and he says he hasn't had sex with her, that they only had an emotional connection. I called BS, but couldn't prove anything so once again, I forgave him and we went to counseling once. Today she so happened to come up on my suggested friends on Facebook and I instantly recognized her face!! But her name was different from what he told me her name was. My husband is very high up in the company he works for and come to find out she's one of his employees! He lied about her name obviously to keep me from knowing that he is jeopardizing his job. I'm so disgusted and hurt. I'm so tired of this girl. I called her phone private and asked to speak with the name I saw on Facebook and she said "this is she" so I know for a fact that he lied. What should I do?