Reasons for Dating
I am simple I date people to have fun. I chose the people I want to date because we would have more fun doing something together than doing that same thing alone.
This may seem over simplified and it is. If I am going to be spending a lot of time, and maybe the rest of my life, with someone I want them to be a person who I can go on dates with and have fun.
Finally I think it is necessary to continue dating the person you are in a long term relationship with. Why stop dating each other just because you aren't dating anyone else. If anything I would want to date them more.