look up any word, like cunt:
 
1.
In prison When a physically weaker heterosexual man enters into a voluntary homosexual relationship with a more dominant male to prevent rape or violence from being waged against him by other inmates.

Such men are said to be "riding with" their respective dominant partners. The same can be seen in female prisons, where an unwilling woman who normally would not engage in sex with another woman would do so for the sake of protection.
" Word in the yard is that Tim is 'ridin with' Big Tony."
by Jem'Hadar June 21, 2009