So interestingly enough, Ali's new "Group o' Five" consists entirely of girls who either have a twin or "double"...Cindy and Mindy (actual twins), Jenna and Sydney ("Two Jenna's") and then there's Ali herself who even if she doesn't have a literal twin, at least has Cece.
So yeah Santa Boxers scene was kinda disturbing. But consider how they all would have got to that moment. It would have been at Toby's beckoning ("So here's the thing - instead of exchanging gifts, Spencer and I are exchanging gestures. So for this to really be effective, I need the three of you to also strip and put these on.") Yeah, Toby will fit in well at Rosewood PD.