Just because she's sporting a new accessory -- a growing baby bump -- doesn't mean Sienna Miller is going to ditch her signature tight minidress to attend "Twilight" star Robert Pattinson's 26th birthday party.
The expecting starlet stepped out in a body-hugging gray dress, showing off her baby bump and her killer legs.
Since a very pregnant Jessica Simpson has given birth to her baby girl, Maxwell Drew Johnson, could Miller be in the running for biggest baby bump in Tinseltown? Not quite. It appears as though the title is currently being held by Alyson Hannigan, who seems to have nabbed the self-proclaimed top honors.
"Congrats to Jessica Simpson! Does this mean I now have the biggest baby bump in Hollywood?" Alyson tweeted.
This will be the first child for Miller and her actor boyfriend, Tom Sturridge.
Check out Miller's growing baby bump below:
Actress <a href="http://www.huffingtonpost.com/2014/04/24/lake-bell-pregnant_n_5204684.html" target="_blank">Lake Bell is pregnant</a> with her first child with husband Scott Campbell.
"Girls" actress <a href="http://www.huffingtonpost.com/2014/06/07/gaby-hoffmann-pregnant_n_5466050.html" target="_blank">Gaby Hoffmann is expecting</a> her first child with cinematographer boyfriend Chris Dapkins.
Kourtney Kardashian is <a href="http://www.huffingtonpost.com/2014/06/04/kourtney-kardashian-pregnant_n_5444993.html" target="_blank">pregnant with her third child</a> with partner Scott Disick.
Jenni "JWoww" Farley
JWoww, who's expecting her first child with fiance Roger Mathews in July, is set to welcome a little baby girl.
Aguilera is reportedly expecting her second child, her first with fiance Matthew Rutler.
The actress is reportedly expecting her first baby with fiance, Romain Dauriac.
Kunis is reportedly expecting her first child with fiance Ashton Kutcher.
Keibler is expecting her first child with new husband Jared Pobre.
Carson Daly and longtime love Siri Pinter are expecting their third child.
Snooki is expecting her second baby with fiance Jionni LaValle.
Milano is expecting her second child, a baby girl, with husband David Bulgari.
The actress is expecting her first child with husband James Heerdegen.
Bilson is reportedly expecting her first child with longtime boyfriend Hayden Christensen.
Bell is expecting her second child with Dax Shepard.