AITJ for calling out two men having sex in the public restroom of a children's playground?

For clarity this is NOT meant as an anti-gay statement. My reaction would have been the same had the people involved been a man & a woman.

I took my 3yr old son to a popular outdoor play area, during a quiet part of the day.

He did a poo in his nappy so I took him to the restroom, which is essentially an outdoor toilet block with two cubicles, one for men & one for women.

Opened the (unlocked) door and two men were in there, broad daylight, having sex. They very hurriedly smartened themselves up & left in a fluster. As they did so I lost my temper somewhat, and loudly told them what they were doing was disgusting, in a child's playground without even locking the door.

One of them turned back and called me a prude and a homophobe, before darting off.

Was in the wrong for calling them out?

TL;DR pretty much as the title says- I called out two men for having public sex in a child's area.