Swimcest 

When people from the same swim team start dating. Typically doesn't end well.

Don't commit swimcest, girl. They always hate each other and stay on the same team in the end.

Swimcest by keith_heathcliff September 8, 2025

Swincest 

The act of incest between two people with the last name of Swinney!

Guy- "Hey Swinney, I'd totally have sex with your sister!"
Swinney- "So would I!"
Guy- "Dude! Thats Swincest!"

Swincest by Swinston January 24, 2011