Nantucket nups

JOE Scarborough and Mika Brzezinski (above) will celebrate their engagement with a bash at the Manhattan home of Steven Rattner, sources tell Page Six. The bash will be on Nov. 9, and we hear that the couple and MSNBC “Morning Joe” co-hosts will tie the knot next spring in a Nantucket ceremony. Rattner’s the financier and former Obama car czar who’s also a regular on their show. Page Six exclusively reported back in May that Joe and Mika were engaged.