confessions of a nurse

so im this nurse in my 30s and engaged to the girl i work with but lately ive been having these wild fantasies about one of the patients. hes in his early twenties, fit as hell and totally aware that i check him out all the time. weve never talked much but i know he knows cause hes always smirking at me when hes gets a chance. last week after shift he asked me if i wanted to talk one on one like a proper date or whatever. but what i really want is for us to go into a private room and just let all the walls fall down. dont get me wrong, id never actually act on it or do anything real to hurt my fiancé. its purely fantasy stuff that runs through my head while im at work. hes always alone when i check vitals cause no one else does his care and every time hes shirtless with just boxers on so i can see every inch of him. i literally have to bite back the urge sometimes when im touching him, feel how hard he is in those thin cotton boxer shorts. the fantasies play out like real life - me getting really intense with him physically and emotionally right there at work. hes always fully awake for it too, watching me strip off my scrubs and get super intimate in his room without breaking any rules or getting caught. i never act on them but damn those fantasies are vivid lately and all i can think about. feel bad cause its not real with him and im already taken so what the hell do i do with this? just venting cos id rather tell a stranger online than my own fiancé.