Why am I having dreams of m roommate and my man in bed together? She has admitted a year ago she liked him ..

Well funny thing is this girl that admitted liking my man now lives with us . And it was her and my man s idea for her to move in with us . Which friends and family didnt agree on especially after her admittin she wanted him to leave me for her but as far as I know nothing has happen between them. Is my mind playing me .