Matthew Lillard

Jay Mohr's Gary may be Unmarried, but wouldn't you know it, he still has in-law issues. Cue the arrival of Matthew Lillard, who will guest-star as ex-wife Allison's brother, TVGuide.com has learned.

Lillard, of the Scream and Scooby-Doo film franchises, will appear in the freshman CBS comedy's 13th episode as Gary's former brother-in-law, Taylor, who has a knack for rubbing his well-to-do status in people's faces. Blue-collar Gary just barely tolerates affluent Taylor's taunts... until he uncovers a surprising secret about Allison's kin.

Despite holding onto, if not building upon, Old Christine's audience every Wednesday, Gary Unmarried has yet to be awarded a full-season pick-up.