Never had any luck with this in First class, one time did meet a girl in business class on my way to Lima who seemed pretty cool and I got her info but never met up with here again (didn't have time). That was on a new years eve flight (we were in the air when the clock struck 12).

Seems that 90% of the people in Intl First are old men.

As was said earlier, usually not the most attractive crowd, any first class lounge in the world will reinforce this.