I used to think it meant something about a relationship, but I guess times have changed. Recently, DS called me and said "Danielle locked herself out of her apartment, so she called me because I have an extra key." After this Mom picked myself back up off the floor, I questioned him and my other DS and found that nowadays, at least in this area, it's a pretty common thing. Yes, DS and Danielle are just friends, as are many other opposite sex key holders (at least among college students).