Zac Efron, The Girl With No Pants & More: Star Sightings 1.22.2016

Oh look. Zac Efon's friend, Sam Miro appears to have forgotten her trousers.

Elsewhere, Yolanda Foster was looking good as she shopped in Beverly Hills, and Simon Cowell posed with fans ahead of Britain's Got Talent auditions in the UK.

See what else your favorite stars were up to in today's sightings.

1. Zac Efron Heads Into Jimmy Kimmel Live! Studios

Zac Efron arrives for an appearance at Jimmy Kimmel Live! in Hollywood on January 21st, 2016 with Sami Miro.

2. Yolanda Foster Shops in Beverly Hills

Yolanda Foster wears head-to-toe grey as she shops in Beverly Hills on January 21st, 2016.

3. Hilary Duff Stops By Coffee Bean & Tea Leaf

'Younger' star Hilary Duff grabs a coffee from Coffee Bean & Tea Leaf in Los Angeles on January 21st, 2016.

4. Matthew Perry Outside BBC Radio 2 Studios

Matthew Perry signs autographs outside BBC Radio 2 Studios in London on January 22nd, 2016.

5. Khloe Kardashian Shares a 2007 Flashback Photo

Khloe Kardashian shared side-by-side of herself with Kim Kardashian in 2007 (left) and the two sisters present day.

6. Joe Jonas and DNC: CTV The Social Talk Show Appearance

Joe Jonas and his band, DNCE appear On CTV's The Social talkshow in Toronto, Canada on January 21st, 2016.

7. Lance Bass and Michael Turchin: Bella New York Cover Launch Party

Lance Bass and husband Michael Turchin at the BELLA New York Cover Launch Party at Troy Liquor Bar in New York on January 21st, 2016.

8. Simon Cowell: Britain's Got Talent Auditions

Simon Cowell poses with fans ahead of 'Britain's Got Talent' auditions on January 22nd, 2016.

9. Malin Akerman Heads Into Jimmy Kimmel Live! Studios

Malin Akerman greets fans before going in to tape an appearance on Jimmy Kimmel Live! in Hollywood on January 21st, 2016.

10. Pregnant Chrissy Teigen Gets Her Fitness On

Chrissy Teigen heads to the gym in West Hollywood, CA on January 22nd, 2016.

11. Ellie Goulding Performs in Hamburg, Germany

Ellie Goulding performs live at the Barclaycard Arena in Hamburg, Germany on January 21st, 2016.

12. Kendall Jenner Gets Out Of Her Car in Paris

Kendall Jenner gets out of her car in Paris, France on January 22nd, 2016.