Friend has been going through a hard time, so I paid £120 for her to join me, DP and 18 other friends on a 3-night mini break.
DP and I were looking forward to some romantic time together. Day before the trip, friend said she isn't comfortable sharing a room with anyone other than me, as she doesn't know anyone else on trip that well. Friend asked to share with me. I said she could share with me and DP. He was a bit miffed but didn't complain, and when we got there he kindly dragged a camp-bed into our room for himself, so friend could share double-bed with me. Room had no lock, so we agreed we'd use a piece of wood to jam the door if friend or DP were getting changed, and that we'd all knock.
Second night, party in full-swing, friend was downstairs chatting with other friends. DP and I decided to have a quickie in room. We jammed door and started having sex standing-up (away from bed and fully dressed). 10mins later friend starts trying to open door, I shouted 'wait we're getting changed' friend ignores this (she was quite drunk) and forced door just as DP is doing up his trousers. Friend doesn't notice anything, she's come to find her lipstick and is happily chatting away!
Next morning I explained to her we'd been having sex in corner when she burst in. She seemed surprised and not pleased. Later that eve, she said she and a male friend wanted to have a 'private chat' in bedroom, we literally thought they meant a chat, thought maybe something romantic was developing so said fine, agreed not to disturb them. 3 hours later I knocked on door, was denied access. Another hour later friend and male friend came out, when I asked her why they were so long, friend smugly informed me they'd been giving each other oral sex and cuddling naked in bed! It was a one-off, she has no plans to see him again.
I didn't say anything to her but feel really really let down by this. We kindly let her share our room, paid for her accommodation etc, yet she brought a man (someone we didn't even know) into our bedroom, got naked with him in our shared bed, and shut us out of room for 4 hours while they went down on each other! AIBU to feel shocked, disgusted and let-down?