He began dating Ashley Biden, a social worker and daughter of former United States Vice President Joe Biden and Second Lady Jill Biden, in 2010 after being introduced by her brother, Beau Biden.[1][4] They married in a Catholic-Jewish interfaith ceremony at St. Joseph's on the Brandywine in Greenville, Delaware.[3] The Catholic mass was celebrated by Father David F. Murphy, who was assisted by Rabbi Joseph Forman.[3] Krein and his wife live in Philadelphia.[4]