Originally Posted by jkelly
People who want kids fall in love with people who don't all the time. As Mono suggested, it may be that they're open to having more. On the other hand, if you're poly- you can continue to have a relationship with this man while looking for a partner who wants to have kids with you. Don't do this if you'll immediately dump your boyfriend to go off and be mono- with this hypothetical new guy! But there are poly- guys out there who want kids.
I was going to say the same thing, but it's already been said. I definately agree that you should just talk to him about your desire to have kids in the future. If he clearly does not want more kids, then you need to cut your losses now and find another partner or consider a poly path that allows you to still have a relationship with him and still find another partner that is willing to fulfill your desire for children. Good luck!