Is it normal to have a vivid dream about having sex with your aunt?

So I had this dream last night about having sex with my aunt. I have had similar dreams before about the same aunt, but nothing this detailed. She and I are not particularly close, she has never married (I'm not married either), and honestly she is not very attractive. I am 30, she is 55. Anyway, in this dream she called me and asked me to come over. When I got to her house, I noticed she was wearing a skirt, which is very uncommon. We go into the living room, I sit on one couch, she on the other couch facing me. She says she has something for me, and hands me a large wrapped box. She says I can unwrap it only if I promise to use the "first one in the box" with her. I agree, unwrap the box, and open it to discover a bunch of condoms. Confused, I look over at her. She has leaned back, lifted her skirt, and spread her legs open. She wasn't wearing any panties. I got up, rubbed her between the legs a little, dropped my pants, slid on a condom, and had sex with her. The dream ended soon after thanks to my alarm clock. I remember thinking (in the middle of having sex) "I hope she doesn't give me an STD" (which, by the way, is a possibility) and "I wonder what Nannie (her mother, my grandmother) would say if she found out?". It really didn't seem to bother me all that much that she was my aunt, I was treating the situation as if she was just some stranger I picked up at a bar, and the thought of how incest (if someone found out) would affect our family never crossed my mind. I swear I did not drink or use any kind of drugs (legal or illegal) before I went to sleep last night. I'm just trying to figure out what all this means, if anything...