A character in a movie who is dating another character who obviuosly isn't with the right character. Originates from the first season of the polular TV-series "Friends" where Rachel is dating an italian guy that Ross calls "rigatoni". Everyone knew that Rachel and Ross should be dating but Rachel dates the rigatoni Paolo instead.
Rigatoni is also a type of italian pasta.
Person 1: That guy Paolo is a rigatoni! I mean it should be Ross and Rachel, not Paolo and rachel!
Person 2: I know!