Fallback boy
A fallback boy is a term used for a boy who has lost all feelings for one of their exes, but then as soon as this ex starts feeling lost and helpless they message the "fallback boy" trying to kick things off again, and most of the time it works, it can be seen as one of the worst ways to be treated for a man as it plays with his emotions.
"Yo, Georgia's messaged me again, should i reply?"
"No! You don't want to be a fallback boy do you?"
"No! You don't want to be a fallback boy do you?"