Generally I'm with friends I have had for years, and we have never made a big deal of any of us guys getting hard. Yes, there are some jokes made all in fun, and accepted the same way. I have heard women discussing between their selves some particular cock, but always complimentary. Some of the larger organized groups are way too uptight about a hard cock.
Gay nudist here for over 25 years. "What if I get hard?" is a common fear but a rare occurrence. I often tell new guys they'll be too nervous to get hard for the first 5 minutes and then they'll realize it's not a sexual situation. Erections pretty much don't happen unprovoked among adults.
There was that time that a youngster of 20 who was on Rx steroids came over and was hard half the evening. We all admired it and razzed him and enjoyed the scenery. We all have dicks, they (almost) all get hard, so it's no big deal.