Will & Grace Actor Sean Hayes To Guest On ‘Up All Night’ August 6, 2012 News, Up All Night Season two of Up All Night has added a new guest star. Actor Sean Hayes of ‘Will & Grace’ fame (Will’s best friend Jack McFarland) has been confirmed to appear, per TV Line, in the series’ sophomore year on NBC as a friend of Ava’s (Maya Rudolph). Hayes’ alter ego will show up in several episodes as a character from Ava’s past who knew her back when she was working in the studio on her music. His guest role sounds casual as he will be hanging out with his old friend once again. Aside from Hayes’ guest stint on the series Up All Night’s second season will also see some minor changes as the show will refocus the storyline on Reagan, Chris and Amy. Also a musician, Hayes boasts a slew of acting credits on his lengthy resume. The 42-year old has appeared in ’30 Rock’, ‘The Bucket List’, ‘Campus Ladies’, ‘Hot in Cleveland’, ‘Portlandia’, ‘Parks and Recreation’, and the TV series ‘Scrubs’. Hayes has also starred in ‘Tom Goes to the Mayor’, ‘Lovespring International’, the TV series ‘Silk Stalkings’, and the films ‘Win a Date with Tad Hamiliton’, ‘Pieces of April’, ‘Cats & Dogs’, and the video short ‘Roberto the Insect Architect’.