new memory - betrayal of friend - not sure what to believe

Mt

I have friend i have known in forever. We grew up together.
He is in army and came back from afghanistan pretty messed up
He was staying with his brother, but his sister in law didnt want him around
So a I let him stay at my place

Teen part hates when he is around....nightmares etc
I thought was just because he gets drunk and angrry at world

Nightmares and flashbacks from teen part have been getting worse
I was bullied as teen and one night at a party hurt badly by several people.
Teen part told therapist that this friend was there and one of people who hurt me and he needs to stay away from us

Having hard time believing it is true. How can I not know something like that???
Been very disoriented since session which ran later.

Not sure what to believe anymore

I would suggest just sit with it and ask Teen how she might feel safer; locking the bedroom door at night or in some way empowering her. Thank her for the information. Trust between you two is important, but so is communication of facts. Trust is hard to build and easily destroyed. Helping her to be empowered will help and maybe you will learn more in time.
Best!