The former Frasier star, who is expecting twins with the ex-flight attendant next month (Jul12), invited 20 loved ones to Drumbar in Chicago, Illinois for the bash, where guests sipped on cocktails and played games.
A source tells Us Weekly magazine, ""Kelsey and Kayte were so cute together - he helped her open every gift! He was by her side the entire time. He was totally into it, everyone seemed like a big cute family.""
Grammer's Boss co-stars Kathleen Robertson, Sanaa Lathan, Jonathan Groff and Hannah Ware were among those who showed up to join in the fun.
The babies will be Grammer's fifth and sixth kids.