The act of two males having intercourse with a single female a.k.a. "running a train" while under the bedsheets. An underground railroad is exclusively when this act is done by African Americans.
"Yo, I heard you and your bro ran an Underground Railroad on Shanockquolisha last night!!"
"Hell yeah! That sh*t was insane!!"
"Hell yeah! That sh*t was insane!!"
by TheOneAndOnlyHalfnHalf October 03, 2011