<human>: My gf and I are both in college and I visit her occasionally.  She had this super hot roommate with an amazing ass. She is on her bed and I'm on my gf's bed. Then she gets down to go and pee and I instinctively grab my phone to take a few shots of her ass. Thinking  my camera shutter sound was deactivated, I press the button which takes multiple shots at the same time. To my horror, my phone gives up on me and she both hears and sees me snapping her ass.  She turns red and asks me to leave her room.. But not until my gf had given me a slap on my face.

Can you provide a brief rundown of the text in within 3 sentences?
<bot>: TIFU by taking pics of my girlfriend's roommate's amazing ass thinking my camera shutter sound was off and got a couple of slaps for that.