While it's usually just the two cat girls hanging out to the point of almost black out where they snuggle together.
Since Neko Nights became popular, the two hired Foxe to build them a Neko Nights Night Club where activities get pretty dang crazy. The Neko Nights also got so big they sometimes over flow out of the club and into the Neko Cabin, a holiday resort for the two sisters.
Several of the community has taken part in these, including Crumbster, KimplE, StealthRG, and many other big names. Nagzz21 had his own drunk night with Lanfear, both of them falling asleep in each others arms. But Nagzz made an unofficially appearance in the second Neko Night, where Oathmeal was so drunk she could barely stand, and Nagzz came in to talk her down and convince her to turn off her stream.
Lucky, after gaining her cat personality, is eager to join her Neko cousins in the festivities.
How to tell when it starts
Usually, if Lanfear and Oathmeal 'pregame', it's a good chance to catch the stream, usually from Oathmeal's point of view.
Usually, Neko Nights doesn't involve RP, unless the two cats sober up enough.