Montpellier, France.
It's the gay capitol of southern europe. It's very inexpensive compared to bigger cities, it's warm all winter and roughly 33 percent of men aged 18 to 30 in the city center identify as gay or bi. Also, of the 50,000 people who live in the city center 12,000 speak English as their native language so it's easy to communicate. It's a pedestrian city so you don't need to drive or worry about driving drunk and it's pretty much impossible to not get laid at night. The last time I was there there were more guys on Grndr than there were in any given area of Paris.