Even str8 guys do it...!
I think it's healthy to watch other guys (regardless of their sexuality). It's also liberating and healthy to let others watch, as too much secrecy and embarrassment cannot be good for any sort of healthy mind or body. As a str8 guy, I would not want to invite anything more sexual, although there cannot be harm in having others watch closely or join in with such a pleasurable activity. Sometimes I think we (str8 guys perhaps more than others) over-think things. This is one of them. It's a simple pleasure. Why not let others see and watch, be aroused whilst doing so and/or join in..and maybe help out if you're relaxed in that environment?
I think people object to the label gay, because their self image doesnt mesh with what they think of as gay. I had a couple that I had regular threesomes with for years. The woman, a very sexy blonde!, would encourage us to take turns eating her while the other fucked and join her in sucking the other. It was mind blowingly erotic and pleasurable . On one occasion, we had both cum in her and were lying on their bed afterwards. I was still teasing and licking her clit with all the cum dripping out. He was licking and sucking the cum off my semi-hard cock and suddenly pulled away and said, I dont think this makes me gay, do you?
I wasnt sure if he wanted an answer, but I told him I didnt think so. I think a sexual person who is open to giving and receiving pleasure is who I aspire to be and be with. I dont think labels are very useful.