An inattentive mother who gave birth to three daughters from three different fathers should not expect to be remembered fondly after her death. In "Seatbelts Required," Kimberly Demmary's new play, currently at the Actors Workout Studio, the three half-sisters, who gather in the deceased's home following the funeral , take turns over the next two hours assailing their mother, fighting among themselves, crying, drinking beer in Act One and Tequila in Act Two, and revealing a few shocking secrets.