My Brother Will Be Mine

My older brother is getting really serious with his girlfriend. We used to spend the entire weekend together, the family joked we were as thick as thieves. My friends are dating guys but I was never really interested in anyone other than my brother. I am starting to think that I might be jealous of his girlfriend, not only is she stealing his time away from me, but what else is he doing with her? Does he wrap his arms around her when they watch a movie together? Does he hold her when she's feeling blue? Does he kiss her soft and sweet like he does to me? Is he having sex with her?