wet week

Don't know about frats but new members aren't allowed to have alcohol at mixers until a certain date. Then when that date comes they have mixers every single night with a loot of alcohol - called wet week

bump

Basically all mixers up until wet week (during official pledging/new member period) are "dry mixers", no alcohol allowed. Starting Monday of wet week, wet mixers are allowed, and to celebrate the end of dry period Greeks have a full week of intoxication. Up there with o-week, Slope Day, and Homecoming in terms of fun.

Sororities all tend to have mixers every single day that week. Frats by no means mix with every sorority during that week, and a lot will have several days off (think about the sorority to fraternity ratio). Wet week mixers are typically also harder to get for fraternities than normal mixers, so frats will typically only mix with there core crew of sororities plus a few "below" their normal sometimes.