Someone who drinks a piscine ('swimming pool' in French) which is a champagne drink with ice.
Moët & Chandon has come up with a special summer offering called Ice Imperial, which is made to be poured over ice (the drink is concentrated, so as not to be diluted by melting ice.) The brand suggests adding fresh mint from the garden and a variety of summer fruits, such as blackberries and strawberries.
A: Are you a pisciniste?
B: Yes, of course. Champagne can never be too cold.
Nicky Santoro, a character in the movie Casino, is considered The Godfather of Pescinomics but most likely this behavior was inspired by the Federal Reserve.
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi