Cock Leash
After an amicable breakup, either party in the relationship feels guilty about hitting on a member of the opposite sex when the other is present, which prevents that person from getting any.
Jack: "Man, I'd try to get with some of those girls last night, but Caitlin was over."
Conor: Man, you gotta get rid of that cock leash.
Conor: Man, you gotta get rid of that cock leash.