speed bump girlfriend/ boyfriend

(n.) A short-term girlfriend or boyfriend; often acquired because the two just want a girlfriend or boyfriend, not because the two actually have a connection; speed bump partners are often teenagers (maybe as young as 13 years of age); a speed bump partner may be acquired just for shock value, e.g. to impress someone; a speed bump partner may also be acquired because he or she has something attractive to another person that should matter minimally in a relationship, e.g. a lot of money.

The term "speed bump girlfriend" or "speed bump boyfriend" gets its name from the idea that he or she works somewhat like a speed bump: it needs to be passed and will come and go quickly.