1. Forget him, because it's a old story and now you have your own family and your own kid to care about. 2. Maintain your family and keep him as a secret lover, because you think you need different kind of love to meet your emotional need, and you can manage quite well the complexity of your relationships. 3. Give up your current and encourage your lover to give up his, because you think your love for him and his love for him is real and true, and you both cannot live without it.
But all in all, remember life is too short to waste and you should treasure what you really treasue. Any take resposibility for whatever you will do.