Lydia R. Diamond's new play juggles issues of race, sex, and class, maintaining high stakes while indulging every opportunity for humor. The daughter of a legendary black academic meets her boyfriend's affluent African-American family at their swank Martha's Vineyard digs. Before long it comes out that she once hooked up with his doctor brother, who's brought his rich white activist girlfriend home at the same time, generating a whole series of hilariously awkward confrontations. Though the pace flags slightly near the end, Diamond swings confidently from hyperarticulate grad-student-ese to plainspoken observation, and seems equally wise to the bullshit of both. Under Chuck Smith's expert direction for Congo Square Theatre Company, every cast member shines. Through 4/15: Thu 11 AM and 8 PM, Fri 8 PM, Sat 2 and 8 PM, Sun 2 PM, Duncan YMCA Chernin Center for the Arts, 1001 W. Roosevelt, 312-587-2292, $10-$25.