I keep staring at my sisters chest. Do i have mental health issues?

you reach a certain age in your life when you can't stop doing something and have bad habits. I am of course a girl and girls don't always quite understand why boys do this. Boys reach a certain age of all they can think about is sex and wanting to have sex with who ever comes along. But of course girls think this sick, sad and girls care about romance, real love and having a good time. My Second cousin Bob is an alcholic but the other day he was sober, he was saying really dirty things to me and couldn't stop staring at my bum. This makes a girl almost freak out and runaway , of course if she's your sister then she won't think you mean anything about it. she is most likely to think "why is he staring at me?" or "do i look that bad?" , just try and not to stare at her in that way. I think your just looking for a real relation ship with someone and your desperate. thanks.