Rebound guy/girl is a guy/girl used on the sideline by an individual if he/she thinks his/her relationship is going to end.
Rebound guy/girl would do anything for you or accompany you once you ask, for instance, having a lunch, seeing a film or going to a concert. Also, they would never go Dutch but take care of you for everything. Apart from that, they are likely to bring you gifts if they happen to be born loaded including luxury bags, laptops, jewelry as long as you are joyful.
Being a rebound guy is a situation that very few men feel comfortable with. Rebound relationships cause a lot of trouble to everyone involved.
I don't really like her; she's just my rebound girl. This rebound relationship doesn't count.