This is usually done out of spite of the blocked male.
Kevin: You should have gone further and cock swapped him.
Charlie: Yeah I should have.......... And... I SHALL!
A cockswapper knowingly uses lies, money, or any other means to steal a potential sexual partner from someone else.
A cockswap can be performed by men and women, however is mostly used as a term by men, as women usually just call the offending party a 'slut'.