They tied the knot in a lavish ceremony at the Kensington Palace Orangery in London in July 2015.
And pregnant Nicky Hilton proved she was well acquainted with the glamorous lifestyle as she attended the Library Lions Event at New York Public Library with her husband James Rothschild.
The Hilton hotel heiress, 34, who is set to welcome her second child in early 2018, dressed to accentuate her bump in a gorgeous figure-hugging midnight blue down as she cut a regal figure for the event.
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Sensational: Pregnant Nicky Hilton proved she was well acquainted with the glamorous lifestyle as she attended the Library Lions Event at New York Public Library with her husband James Rothschild
Clearly dressed to command attention, Nicky oozed elegance in the slinky backless number which boasted a frilly draped neckline.
Complementing the number, which put focus on her blossoming bump, the sister of socialite Paris Hilton swept her blonde locks in a chic side-parted chignon.
She opted for a glamorous coat of make-up, consisting of mascara-laden eyes and chiselled cheekbones.
Proving to be her best accessory, James also ensured he was suited and booted to perfection.
Glamorous: Clearly dressed to command attention, the Hilton hotel heiress oozed elegance in the slinky backless number which boasted a frilly draped neckline
The expectant pair looked to be having a great time as they made their way up the stairs.
The socialite is already a doting mother to baby daughter Lily Grace, 16 months, with her second child set to arrive in early 2018.
Nicky said she and James won't be finding out the gender of their little bundle of joy, but she insisted she would be 'thrilled with either'.
Speaking last week, she told US Weekly: 'You know what? I would be happy with either but I love having a sister. With a sister, you have a best