Girls star Allison Williams and John Mayer hit the town together... as Katy Perry recovers from her inauguration exploits

Musician John Mayer has been spotted with Girls beauty Allison Williams - just days after partying with girlfriend Katy Perry at the White House.
The singer, 35, and the willowy brunette, 25,  who is dating Mayer's good friend Ricky Van Veen, surprised onlookers as they turned up at an intimate event for fashion store American Two Shot at Manhattan's trendy Jane Hotel on Friday night.
The couple are longtime pals and enjoyed dinner with their respective partners in New York last month.

Stunning: Allison Williams wears Oscar de la Renta to appear on ABC's Live With Kelly and Michael on January 18

Dinner companions: John Mayer, left, Allison Williams, and a friend have dinner at West Village hotspot El Toro Blanco on Friday night

An onlooker told MailOnline: 'Allison and John walked in together and separated to talk to respective friends.
'They then made their way back to each other, and John had his arm around Allison's waist. They were talked together for a bit before leaving.'
The onlooker said Allison, who stars as Marnie in Lena Dunham's HBO hit, had her hair in 'polished waves', and was wearing a beige suede jacket - while John had donned an odd 'beige dressing gown-style coat.'
The pair left the event - where there was red velvet cake and bacon vanilla sponge cake to celebrate the store's anniversary - and headed to dinner at West Village Mexican hotspot El Toro Blanco.

Buddies: Ricky Van Veen and John Mayer at a film screening in New York in March 2011

Guest list: India and Eric Benet, right, are pictured with John Mayer and Katy Perry at the White House afterparty. Benet's wife Manuela Testolini poses left

All smiles: Smitten couple John Mayer and Katy Perry celebrate at President Obama's second inauguration

There, another onlooker told MailOnline: 'They were with another guy, but they seemed to be in an intense conversation the entire night and were sitting across from each other at the booth-style table.
'They were sitting down when we got there for our 10pm reservation, and they stayed until around 11:30pm.
'They stayed pretty the late until the restaurant was clearing out.'
Allison was first linked with boyfriend Ricky, CollegeHumor founder and CEO, in May 2011.

Celebrating: Allison Williams, Lena Dunham, Zosia Mamet enjoy their Golden Globes win at the HBO Golden Globes after party in LA this month

Red carpet beauty: Allison Williams wowed in a sleek black J.Mendel gown at the Golden Globes

While John has been dating chart-topper Katy, 28, since June and has been helping her to recover from her divorce from Russell Brand.
The couple partied with the Obamas last week after being invited by President Obama and First Lady Michelle Obama a star-studded after party at the White House following the inauguration festivities.
Teenage Dream star Katy, who performed at the Kids' Inauguration Concert, posted a diary of her exploits in Washington D.C - with John by her side. She then tweeted: 'Just left the White House. All other parties from here on out will be judged unless they take place at the White House.'
In an intimate diary for Vogue, the star posted pictures of her cuddling up to John as they celebrated President Obama's second term in the Capital.
A source close to Allison confirmed today: 'Allison is friends with John and Katy,', while a source close to John said they were 'longtime friends.'