05/28/2012 at 05:55 AM EDT
Kelsey Grammer's wife Kayte Walsh hasn't even given birth to their twins
yet, but the actor is already a doting dad.
After cutting the ribbon to officiate the grand opening of Davidoff's first American cigar lounge on Thursday, Grammer was "so friendly" as he chatted with fellow guests about how excited he is to be a dad again, according to an onlooker.
"He was also saying that the twins are expected in July, and he'll be heading back to L.A. for their birth," the insider explains to PEOPLE of the Boss
star, during the private party, located at Humidor of Westmont, right outside of Chicago. "He happily posed for photos with guests, but didn't drink and overall kept a calm and easygoing composure." – Dahvi Shira