Undercover brother 

A straight man who goes out and/or secretly has sex with men behind their girlfriends/wives back

My lax bro Kevis such an undercover brother, he stops by gay bars every night to hook up with dudes behind his girlfriend s back.

Undercover brother by lil leroy October 23, 2022

Undercover Brother 2

synonym for "stalled in production"

I can't believe G-Union wasted good money watching the first in this Undercover Brother series to begin with! He must not have an appreciation for Mandy Moore movies.

Undercover Brother 2 by diction July 15, 2003

brother undercover 

rich guy pretending to be a working man

" I didn't know you were a Brother Undercover"

brother undercover by pinchemotherloaf August 20, 2013

Undercover Swedish Brother 

When one takes a dump onto a bed prior to engaging in sexual intercourse with one's partner on top of the soil without the partner knowing.

Henry: Dude, I'm about to get laid but I really need a shit. What shall I do?
Harry: Just be her Undercover Swedish Brother!

Undercover Swedish Brother by yes!yes!yes! March 20, 2014