Mixer drinks are a mix of spirits with soft drinks, most commonly lemonade. These drinks are extremely easy to consume due to the soft drink content and there for are a typical starting drink for underage teens. They are also extremely pussy drinks and are quite popular with the ladies and the fags.
Lance and his friends headed into the nightclub looking forward to a good night of partying until they noticed that something was terribly wrong, all the guys were consuming mixer drinks. Clearly they were in a gay nightclub.