While Allison Williams looked gorgeous at the Vanity Fair Oscar Party, all eyes were on her huge engagement ring.

Williams debuted the diamond sparkler while posing for photos in a stunning coral gown outside the party in West Hollywood. The "Girls" actress and College Humor co-founder Ricky Van Veen confirmed their engagement Feb. 26.

The 25-year-old and her beau have been dating for three years, according to Us Weekly, and she is apparently ready to start her own family.

"My goal is to create a career I can walk away from and become a mom," she told Glamour for the magazine for the March issue. "I'd love to be a mom -- and not have to bring my kids into my trailer ... Or a balance [of both]. But you've [got to] call it on the fly to a certain extent."