What is the current one-night stand protocol?  Do you disappear into the night or stay till morning?  What about breakfast?

It’s whatever you and your partner(s) want it to be.

There’s no “Official Board of Hookup Protocol” issuing decrees about proper booty call etiquette and assessing fines if unspoken sexy time manners aren’t observed. If all involved parties decide together that everyone should stay till morning and have breakfast, leave after you’ve all finished, write each other thank you notes, or give each other presents and awards, that indeed is your one-night stand protocol. Everyone not hooking up with you has no say.

If you’re unsure how to be polite in this situation, you can always ask your partner(s). (“Hey, I’m unsure about how we should part. Would you like me to stay till morning and have breakfast or leave shortly after we’re finished?”)