Dreaming about my ex-bf from 6 years ago?

have been dreaming about my ex. For six year straight and it is always the same dream. It is so vivid it almost scares me. His smell, touch, kisses, the way he looks at me. All of it the way his skin felt. and i wake with a huge smile on my face and this feeling of uforia, and bliss. the most happiness i have since in a long time. to the point were i find my self trying to go to sleep soon and longer just so i can see him in my dream. last night i a woke and was so turned on like never before. any ideas why this is happening. but they are just like real life. they feel so REAL.. its uncanny to the point where i forces myself to take a nap just to dream............................