Addicted To Him

I need someone's advice... Here's my situation.

Two weeks ago, i hooked up with this gorgeous skater guy, and now i've become completely infatuated with him. i'm not just physically attracted to him, but he's so intelligent and athletic, and ambitious...

His sister, is a girl at my school, who, to say the least, isn't my favourite person. She keeps asking me if we had sex and what actually happened. I dont answer her, and try to ignore it. But she's begun saying that now i've prolly got diseases from him, and saying about how much of a bad person he is... It doesn't worry me, because i didn't sleep with him... But i'm just getting really upset because i like him so much! We connected that night... And i dont know why anyone would say anything bad about him...

What do i do? i want her to leave me alone, with my thoughts of him...

More than likely you know his reputation with girls.

Go by that, boys lie their asses off.