I saw one guy about a year ago, as he worked at a facility that cater to mostly gay men. Although I don't know if he's gay or not, but with the nail polish and his work place combo, I would just assumed he's or at least bi. For me, everyone is free to do what they feel like with their own bodies, legally, but for me there is a limit of what a guy should present himself.
Nail polish can work if it's done in a good way. The guy I worked with, he's straight and told me that sometime he got his nails done in a professional nail salon and get all his finger nails painted white, without looking closely, no one would aware that he has nail polish on. I didn't. The guy I saw last year, he had red, gray and white alternatively on each of 10 of his fingers and just very distracting looking at them.