Once a week, the Washington Post’s Date Lab matches up two singles in an effort to prove how difficult it is to spend a few hours with a stranger. In one of this ongoing experiment’s highlights, a dater said she was going to the bathroom and never returned—a harsh choice, but given Date Lab’s track record, at least a time-saving one. Even would-be lovebirds subjected to less dramatic fallouts face embarrassment in the D.C. area: Rate your date too high and come off thirsty, rate too low and read as frigid. How does the Date Lab crew get it so wrong every week? Find out from Post “matchmaker-in-chief” Christina Breda Antoniades, who will chat with Post advice columnist Carolyn Hax (pictured) and pro matchmaker Paul C. Brunson on love and, presumably, why Washingtonians continue to submit themselves to the column’s amateur but highly readable matchmaking. Later, eligible singles will compete in a live dating game. The “prize”: an evening out on Date Lab. The event begins at 7 p.m. at the Newseum, 555 Pennsylvania Ave. NW. $25. (202) 292-6100. newseum.org.