Ha, that was great. None of them could keep a straight face
Hader later said that in rehearsal, Fred Armisen delivered his "What're you doing here!?" line normally, but when it came time to air he said "Whhhhhhhhhhhhhhat're you doing here!?" and it threw both him and Kristen Wiig for a complete loop. There's a history of SNL performers mixing stuff up ever-so-slightly to get their castmates to break, Chris Farley did it to David Spade in one skit.