Mum and i are in love?

Before I tell my story, you need to know this first: My mum and I are extremely close. My little brother and I are close. My father and I are average. My brother does not like our father but he loves me and our mum. Okay, here's the story:

Last fall, I moved back in with my parents after being passed back & forth to my aunt and uncle. My brother was staying with my parents or with my father's ex-wife. I've also gained a strong interested in BDSM, well not necessarily bondage but definitely me being the submissive one and an attractive, authoritative female figure in my life would be the Mistress (master). When I moved back, my mum and I bonded quickly while my father and I took our time. I'm close to my little brother who is 13 but we get jealous if one of us is spending time with our mum. I think my mum knows this yet she doesn't stop it. I guess she finds it rather amusing or rather it makes her feel sexy. I've noticed that my mum and I are growing more fond of each other to the point where we hate being separated from each other and if I'm out with my friends or a guy, she's very aloof and I think she's mad at me. I've always been the type who puts important people in my life first before myself, and I still do that. I want to start college soon but I'm afraid to leave my mum behind. My friends tell me they notice I always want my mum and if I'm not with them or my brother then I'm with my mum. They think we're inseparable. My mum and I are very affectionate; you'd know something was wrong if you found us not holding hands, hugging, cuddling on the couch, etc.

I guess I'm writing because I know this isn't normal but at the same time, I just don't know. I'm wondering what your thoughts are and what I should do. I also worry that my brother is falling in love with my mum. She doesn't seem to be interested in him. She's been in love with my father for quite some time but he hasn't been the romantic or passionate type lately.

She's 34, I'm 20, my brother is 13 and my father is 40. If it helps, my mum is half Scorpio half Libra; I'm more Scorpio than Aquarius.