My crush's friends keep teasing me about him?

I swear my situation is unique. Actually back in February my crush returned me back the love letter that I had wrote him at the end of the previous year and said that he wasn't interested in a relationship with me. I though well that was sweet, he said it in the nicest way possible and it showed a sense of maturity that was rare to find in a teenager. In fact it had made me fall more in love than I was ever before. Slowly, slowly in a span of 2 weeks he had started seeing me less and less until he started avoiding me. We both go to different schools and he shares the same school as my very young cousin in year 7. I go to pick her up sometimes, and when I do on occasions I happen to walk nearby my crush and he looks back to look at me everytime. He probably thinks like last year, I've come to run into and talk to him, but I'm not interested in boosting his ego. The other day however, I went to pick up my cousin again and his friends walked by me, and when they did, very loudly they said "Have you seen *crush's name* lately", and again when they drove past me they said his name in a conversation very loudly. I don't know what they want, does my crush think I'm still desperate that I come to his school everyday to see him (which is kind of true, the reason why I agreed to pick up my cousin in the first place)? And why are they teasing me, I just don't understand, is my crush now interested in me suddenly or what???