If you're looking for a town with water I would recommend Milford, CT. While it doesn't count as coastal it does have multiple beaches, good schools, safe neighborhoods, a mall, a movies, and a train station that can get you directly to NYC.

Downtown Milford is a great place to rent. There's a beautiful green, lots of restaurants, and the train as I mentioned (your boyfriend might want to visit Brooklyn or even just Manhattan).

It's just something I wanted to throw out there.