So I had moved to another city and it was the same at the swimming hall. Someone tried to talk to me in the sauna. A dark guy with moustache in his 50's. Stylewise he was not very unlike Joseph Fritzl but he was younger - healthier of course, and had a rounder face. He had a nice charming smile. It's not hard to imagine he uses poolhouses to pick up young guys regularly.
His checking me out became unbearable and I switched to the other swimming hall, whereupon he started going there instead. He was a lousy swimmer but he was pretty big and imposed some kind of real threat.
He continued to check me out for while until I took my girlfriend (at the time) there several times and sat closely with her in the jacuzzi, I also made friends there - in the end he lost interest. I saw him downtown several times after that but he never gave away any sign that he recognized me. It was several sightings in exactly the same place - a well guarded (literally!) spot in central city - he always rushed forward with a briefcase.