I've known my boyfriend for a long time but we've only been together for 2 months. I really do love him and he's proved to me that he really does love me too. But I found out the whole time we been together he's had another girlfriend. He says he doesn't consider them together because they never saw each other during the two months. He says he never liked her he just didn't want to break the news to her because she was going through a lot. He finally broke it off with her when I found out about her. But I've questioned her to him multiple times and he never took the opportunity to tell me. He denied her and he lied to me. I don't know how to trust him now and I don't know if I should be mad at him for being a nice guy or mad at him for lying. I don't know if it was a mistake taking him back. What should I do?

How long have you known your boyfriend for. You said a long time but you do not specify how long. 2 months in not really a long relationship. Could be was testing the waters before making a leap either way. Not justifying the behavior just stating what his intentions might have been. Did you ask him why he lied to you? You questioned him, does that mean you suspected he was with somebody else even without him telling you?

Did you specifically take him back? If so no one can say whether that was a mistake or not. Only time will tell. You have already made some decisions. Are you willing to move past this, even though there is trust issues there because of his lying.

What does he mean he never thought of them as together because he and her were never together for the two months. How is this possible? If they were not seeing each other how are they together?

I can understand maybe Saving someone's feeling if they are going through a rough patch

He should have been honest with you

The main question is here is

If you want the relationship to go on you have to forgive and pretty much forget
A relationship can not work if there is trusts issues if you feel that you can not honestly trust him again
Then break it off

Talk to him tell him how this has made it hard for you to trust him. And see where you go from there

I take I you guys was friends before and only recently started dating?

Be honest with yourself and with him is this something you can let go?

By his own words, he lied to her, and he lied to you. I would trust him either, and surely would never trust him with my heart.

Be honest with him, as he wasn't with you, and tell him your trust is broken, and see if you can put your heads together to repair it, or go your separate ways.