It was a Duff sister's baby dinner celebration the other night as Hilary threw big sister Haylie a party in honor of baby number two.

The Younger star was all smiles as she celebrated with her sister and brother-in-law, Matt Rosenberg, who are expecting their second child together. Haylie looked very pregnant in the photos on Instagram, which could mean the little one is arriving sooner rather than later.

“Last night my sister threw me the sweetest celebratory dinner for our new baby girl! AND I hardly took any photos. A good sign of a great evening! Thank you @hilaryduff," shared Haylie in an Instagram post, along with some photos from the night.

Haylie was not the only one who showcased the special evening on social media. Hilary also shared a loving photo alongside her sister. The siblings were all smiles as they celebrated the joy of a new baby who will be joining the family soon.

The 33-year-old and her husband revealed back in January they were expanding their family. They also shared they are expecting another little girl. Yes, Matt is going to be outnumbered even more in their little family.

"Round 2! Ryan thinks our new baby is growing in HER belly! #FamilyOf4," Haylie captioned. She also included a photo of the couple’s almost 3-year-old daughter Ryan Rosenberg.

Those Duff sisters proved once again just how close they are with each other. Hilary threw her big sister Haylie a dinner to celebrate her second pregnancy. She also shared how excited she was to be with her sister and celebrate her new niece, who will be making her big arrival this summer.

The expectant mama was quick to thank all of those who came to celebrate her and her growing family, with a lovely message featuring her holding her growing baby bump.

“Thank you to everyone that came together yesterday evening to make me feel so loved & special. This little girl has so many wonderful “aunties”.. she doesn’t even know how lucky she is yet...” Haylie expressed.

There is going to be another girl in the Duff family and the famous sisters had an awesome dinner to celebrate.