The 28-year-old royal was spotted partying with the former Pussycat Doll, 31, his cousin Princess Beatrice and pals including reality TV stars Hugo Taylor and Spencer Matthews from 'Made in Chelsea', and buying a round of shots for the bar at Bodos Schloss, which is owned by his close friend, Thomas Van Straubenzee.
A source told USMagazine.com: ''Harry was having a great time drinking with his friends. He had a good ol' flirt with some cute girls, including Ashley Roberts from Pussycat Dolls, but it was just banter and he spent most the night with his friends, and Bea, in the VIP area.''
Harry reportedly took a regular cab home and wrote a personalised message to his driver's daughter, which has since been posted on Twitter. In the note to teenager Mickie Jayne, he wrote: ''Dear Mickie, your dad loves you . . . teach him to drive properly!'' He also wished a her friend, Callie Connelly, a ''happy b-day.''
Ashley is living in London while she acts as a judge on 'Dancing on Ice' and she recently revealed she loves British men.
She said: ''British guys are amazing although I haven't met any yet.''
The singer also hinted that she might consider staying in London after the ITV series.
She said: ''I've got another four weeks of Dancing On Ice but when that's done, who knows? There's a few things in the pipeline but I'm excited to see what's next.''