Beau is Combs' & wife Nicole's second son, after 1-year-old Tex.
The Mean Girls actress showed off the nursery made in collaboration with Nestig.
Along with a winking emoji, the Blink-182 drummer commented on the new baby bump photos: "I already know his name."
This will be the first baby for the couple, who each have children from previous relationships.
"It's the right time for her, and Bader is an angel," the Lohan matriarch says of Lindsay & husband Bader Shammas.
