If you are not a JW and he is, it could be the biggest mistake of your life. JW's are only supposed to "see" other JW's. If he still says he is a JW and has JW family, then he will still want to please them and most likely would not tell them he is seeing a non-JW. Dating like this is a complete no-no for them. If you really like this guy and it actually leads to marriage, there's a chance he will try to get you to become a JW. If you don't convert and he continues as a JW, there will be many problems in your marriage. You can read countless stories of JW/Non-JW couples and the lousy marriages they are stuck in on this forum.
My advice is to run for your life while you can.