Well about a year ago my gf cheated on me with my ex bestfriend and i just found out a month ago she said that she was mad at me and we were fighting that night, well i feel asleep cuz i was drinking and pass out on the couch in the living room later on the night her n my ex bf were alone together and he starting telling her she was pretty and all that bull**** so she decides to give him head and she did stop after a minute she said and felt bad after that, she did this while i was only like 10 feet away. she never told untill my other friend told me she dinied it at first but then told me everything. im hurt so much by this becuase we have been together for 5 years now and we been through alot and im a very forgiving person and just trying to make sense of all this right now. I belive that she is sorry and remorseful about the whole thing. I know were all not perfect and try to learn from our mistakes. Im asking myself should i give her a chance so we could try to fix things and try to start new, we also have a wonderfull little 4 year old girl who just by looking at her i can get some sort of peace when im around her. I need some advice and probaly someone whos been through the same thing and can explain how they handle it. Should i leave or stay please help. thank you i look foward to some great reponse

my ex cheated on me and she also did it with my best friend while i was in the other room asleep she blew him and not care, she said at that time she didnt care after she just saw me like not even 30 seconds ago she blame it on being drunk a stupid she also says she sorry and told me she would never do it again it was a bad judgement.
We have been together 5 years with a 4 year old kid what should i do needing help and advive