To dress up in a typically metrosexual fashion, go out, and get drunk whilst attempting to meet women. This is different from typical metrosexual and/or male behaviour in that it occurs much more often than is considered "normal." In other words: Nightly.
This term is named after an irc entity who, in his normal channel, has become invariably associated with this activity.
"So, you going to nelluk this week, or just lay low?"