TIFU by asking my sister for sex and grabbing her ass

I know it sounds bad. It is bad.

This happened about three months ago. For context I live with my girlfriend in an apartment with one bedroom.

My sister was visiting from out of town. She said she’d sleep in the couch. I thought that would be that. We ate dinner, chatted, had a good time. When it was time to go to bed, however, i was feeling horny. I turned off the hall light and then opened the door to crawl onto out Queen size bed. I don’t see shit. So I crawl in on my side, wait a few minutes, and then it happens.

I turn to my girlfriend. Her back is facing me. I grab her ass and whisper “I’d love to fuck you.” those exact words.

Turns out my girlfriend is a good hostess. She had offered to sleep on my couch instead of my sister. I ended up grabbing my sister’s ass and telling her id love to fuck her.

My sister turned to me. “Max?” I recognized her voice.

I hoped out of bed. I was mortified. I ran into the living room and, sure enough, there was my girlfriend. I ran back into the bedroom and apologized to my sister. We both got a good laugh out of it, at least, even if I was laughing through the tears.

TL;DR My girlfriend and sister switched rooms without telling me. I ended up grabbing my sister’s ass and saying I’d love to fuck her.