My educated guess: every few years Hugh would pick a Playmate of the Month to be his girlfriend(Barbi Benton) or wife (Kimberly Conrad.)
Maybe that prevented Hugh from a "consecutive record."
A little more research reveals that the mother of Scott Caan was not a Playmate of the Month, but simply a Playboy cover girl. So Caan got Playmates AND other Playboy models.
A little MORE research reveals that Caan actually lived at the Playboy mansion for awhile after a divorce.
And yet MORE research finds a funny video on YouTube of Don Rickles entertaining a small crowd at the Playboy mansion including Hef, James Caan, and "the man of the hour" Get Smart star Don Adams.
Rickles says, "I look around the room and I realize I'm the only big name here," and then corrects himself: "No, wait there's Jimmy Caan, asking Coppola....'let's do Sonny again...we can pick 200 bullets out of his ass."