Just re-think before you proceed, how you planned and waited to build a good name, how you showed your interest, how you dreamed to have them as your partner. you guess, everything is waste for now?
ok, Lets proceed,
do not initiate any new topics with them,
do not share your pleasures with them,
do not phone them,
do not listen what they are talking with you,
just do one word replies only,
do not suggest/comment or recommend anything,
talk more with other than them,
just move somewhere, once they approach you in party,restaurant,school or anywhere.
above are just cutting your relationship with them in a decent way, i do not recommend to hurt or irritate them, so please, do not irritate them with their personal information.