I wipe my butt after diarrhea with your bathrobe
I spent the night at your house and the first thing I have to do when I wake up is run to the bathroom for a diarrhea attack (one fast jet of diarrhea can be heard). My belly's on fire..
You're still asleep and luckily you don't notice anything.
Once I'm done, I grab the toilet paper and I realize the roll is over! What a nightmare! What should I do now? I don't want to wake you up and let you see this horrible show! It's the first time I've slept at your place. It would be too embarrassing...
Oh, I have an idea! I see your bathrobe attached to the door, and I decide to use that. With my pajamas down at the ankles, I move to the door and wipe my diarrhea-stained ass with your bathrobe. Now I just need an excuse to leave as quickly as possible before you realize what I did!