I have been with my wife since college and I lived with most of my best friends to this day while I was in college. She would regularly walk around our place topless in the mornings after our parties. It gave everyone in the house a pick me up and I think she got fairly turned on doing it as well. My buddies girls did the same from time to time so I didn't really think anything of it. Slightly awkward when I ended up marrying her though.
I was hammered one night and took the attached pic which she insisted on sending to a bunch of my guy and girl friends. Was literally referred to as "nipples" since then in front of me to this day and it still turns me on.