At the hospital, Kevin's drink changes from clear to dark between shots.
Kevin tells the doctor that he wants "Meghan Markle-level attention" for Kate and the group jokes about her. Randall says something about "baby Markle." The child of Meghan Markle and Prince Harry will not be a Markle but a Mountbatten-Windsor.
However, Kevin was either drunk or under hangover and trying to make a point, clearly not caring enough to fact-check any royal baby's surname.