Double Duvet 

When your partner kicks their half of the duvet over you, so you are then covered over by a double layer of duvet.

I got no sleep last night because of the heat, as my girlfriend double duvet’d me

Double Duvet by Sheepdawwg July 16, 2019

Double Duet 

When you and your partner have sex in the same room as someone else and their partner - but you don't swap.

Me and you had sex in the same room, but didn't have sex with eachother's partner. Did we have a Double Duet?

Double Duet by Big Dave on the mic December 4, 2016