Kids are fine if you provide consistent and truthful age-appropriate information to them. How much information to share with them about their own origins is something lots of parents navigate now, with adoption, surrogacy, and blended family situations becoming so much more prevalent. In terms of telling your kids that two men or two women can be together, that's something that many parents are teaching their kids now, even if they are a heterosexual couple, because they want the kids to know that gay people are just like everyone else and it's ok if the kids themselves are gay.
There are better and worse places to be a same-sex couple with children, particularly two men raising a child (as opposed to two women), but that's not really too difficult a task these days - finding a comfortable place to live where you don't have to worry about your kids feeling like the "only" ones being raised in a gay family.
The only caution I'd throw out there is that if your partner has not yet found a comfort zone with how you are viewed in society as a same-sex couple, then you are probably going to make this situation much much more difficult by introducing a child into it. In fact, it sounds unstable. No one should be forced into any labels that they don't identify as, and it makes a lot of sense that your partner is not gay and does not feel himself to be gay. However, at some point, he would need to make peace with the fact that while he may not be gay, the world will see him as being in a gay relationship. Period.
Having kids is a surefire way to call public attention to your relationship in ways that you may not even realize as someone with children. This is particularly true for two men. The "norm" in our society is that when a woman cares for her child, she is parenting, and when a man cares for his child, he is babysitting. When you have kids, strangers approach you to ask questions or make comments. When people see a man caring for his child, they ask the kid, "oh, are you with your daddy? Are you waiting for mommy?"and all sorts of other stuff that is intrusive and presumptuous of a heteronormative standard in which women are primary child-rearers. People do not make the same comments or assumptions when a woman is alone with a child asking about "where is daddy?"
While society is more accepting now of same-sex couples and same-sex parents, the reality is that you are forced into commenting on your family situation, in public, by casual, well-meaning strangers all the time. How you handle those questions and comments will influence how your children view your family. And if your partner is not capable of being seen as one of two gay daddies, then you're going to have some problems.
