I usually jump all over these legal inaccuracies, but in this case I don’t think it was necessarily inaccurate. Virginia's age of consent is 18, so my guess would be that the hotel was actually located in Virginia, not DC. DC is tiny (roughly the same size as the City of Richmond) and a lot of what most people consider to be “DC” is actually in Virginia or Maryland.

Man, with both of Gibbs’ rules #1, her rule #1, Abby’s rule #1 and Tony’s rule #1 it’s a miracle that anyone can keep them straight haha