Its not something you really see, most people are just there for the party. I’ve seen people having sex in a foam party and on Salinas beach but I don’t think I’ve ever seen people doing it anywhere else. I’m sure people do, but maybe they’re doing it discreetly.
Never done it anywhere mad in Ibiza myself, but back in 2001 my brother did the deed in the sea outside Bar M at about 2 in the morning. All their clothes got stolen-so they had to run through san antonio with just their underwear on!