Dorit and Paul “PK” Kemsley’s split was a long time coming. According to insiders, The Real Housewives of Beverly Hills stars separation was not as shocking to the people closest to them. “They’ve been having serious problems. Dorit is often left home with the kids [Jagger, 10, and Phoenix, 8] while PK’s traveling, and it’s like they were living separate lives,” the source spilled. The fashion designer revealed during the RHOBH Season 13 reunion that the music manager’s drinking habits had become a bone of contention between them. “PK’s drinking was another issue; he stopped but there’s always…