Joseph Baena — the love child of Katherine’s father, Arnold Schwarzenegger, and the family’s one-time housekeeper, Mildred Baena — posted “Congratulations!” on a photo on Katherine’s Instagram, adding two hearts and a champagne-bottle emoji.
Baena, now 21, and a true lookalike of the former governor of California, was noticeably absent at his half-sister’s San Ysidro Ranch wedding in Montecito, Calif., on June 8.
Katherine’s siblings Christina, 27, Patrick, 25, and Christopher, 21 — all born to Arnold and Maria Shriver — were in attendance. But according to a source who has worked with the family, the new Mrs. Pratt, 29, and Christina “have really no relationship with Joseph. I think the sons have more of a relationship with him.”
Recent college graduate Joseph — known to pals as Joe — yearns for a connection with…