Brother/Best Friend Dilemma!

[Gaynor]

Ok peeps, not been on her a long time but have a big dilemma I need some help with.

My brother is going out with my best friend - they have been for years, and moved in together last year. I broke up with my ella of 2 years over xmas, and went to stay with them until I moved my stuff out etc. Anyway, I was due to move out in May, but last night I got home early but had a nap when I came in. I guess nobody realised I was in, and I awoke to groaning noises. I presumed they were at it, but I needed the loo and to get there I had to pass their doorway. Presuming the door would be closed, I quietly went to the loo.

I was mortified to see the door open, but I thought I could pass by discreetly. As I passed, I looked in to make sure they didnt see me, and was horrified to see my brother romping with a man. I didnt recognise the man, and luckily they didnt see me. I stayed in the bathroom until he left which was an hour later. When my best friend came home, my brother wrapped his arms round her and acted as though nothing had happened.

I really want to tell my brother I know about it, and I feel a duty to tell my best friend as well. I feel very stuck in the middle, and might be moving in with my parents this weekend as I dont think I can stay there till May knowing what I do. I told them I might be moving out early last night, and they both got upset and think its something to do with them - which it is but I cant say exactly what.

What should I do! Help!