Hi everyone,

I am thankful to have found this forum to express my doubts and hope i can get advices from you.
I have been with my boyfriend for almost 3 years, we live together with my 9 year old daughter from a previous marriage.
I do believe my boyfriend deeply loves me.
But last week he lied to me and spend the night drinking with a female co worker.
When he goes out he tends to drink without end, up to the point that several times, he ended up drinking all night outside and forgetting completely about me, not calling, and going to states of high drunkness. It happened maybe 4 or 5 times in 3 years but 3 days ago it went very far.
Friday night, he was supposed to spend the night with me as he promised it would be a special night of love after a rough period during which we barely had time to see each other.
I was full of hope we would spend a beautiful night of love. He promised he would be back at 8.30pm from a drink with co-workers in Manhattan. He called me around 8.30pm telling me he would be late, then called me at 9.30 saying that he would rather stay with his co-workers talking about work because it was much needed. I was upset but thought he would come back around midnight.
But no. From 9.30pm to the next day he did not contact me. I woke up at 2 in the morning to find out that he had not come back home. I waited until 6am extremely worried. He finally called me at 9.30am telling me he did not know what happened but he got too drunk and ended up sleeping at his male co-worker's place.
My intuitions are very strong and i felt something was wrong.
Later i called his male co-worker to found out that he did sleep at his place. The male co-worker left my boyfriend and his female co worker Eva together at the bar at 11pm.
So my boyfriend lied to me about where he spent the night. He lied to me several times, made up a whole story with a lot of ease.
All of it was lies. After i confronted him, he finally admitted his lies and told me he lied out of fear because he realized he should never had gone to the co worker place to spend the night drinking with her.
It seems that what happened is that he was already quite drunk when he acepted the invitation of his female co worker to go to her place to have more drinks and chat. It was around 2am. They took a taxi and they drank more glasses at her place until he got really sick and threw up in her bedroom.
Now why this girl invited him to her place late at night instead of sending him home to be with his girlfriend? Why did he accepted her invitation? Why did he never called me or seemed to have thought about me waiting at home for him all night? Why did he keep drinking with her and why did he end up sick throwing up in her bedroom? He told me nothing happened and that after him throwing up she gave him sheets to sleep in her bed and went to sleep with her roommate.
Now his co worker seems to know that he has a girlfriend. How can she invite him who is her boss to drink with her at her apartment?
I called his co worker and she was petrified when she heard me asking what happened. She said they drank too much and that he was not managing himself well. in that case, why she invited him to her place? He must have been still able to go in the taxi, chat with her for a few hours before getting totally sick with drinking.
I apologized profusely and says he needs to understand why he drinks to the extreme sometime. But he totally minimize how bad his behavior was.
I am lost.
Please give me some advices...
Should we move on, put this behind us, and trust him again or should i listen to my heart that says he went too far?

Thanks for your help,
Emilie