Partner is not motivated

My partner handles priorities very differently than I do, and it’s making me wonder if I want to be with him. We have been trying for a child, and most of the payment toward fertility treatment has been covered by my insurance, which he’s on. He’s paid for things out of pocket, but 90% of the costs have been paid by me. When I brought up with him that I would like him to contribute more financially to the cost of fertility treatment, he told me that he would be contributing when the child was born. I didn’t really know how to respond to that. He’s never stepped up by offering to take on any type of extra work to pay for fertility costs. When we were going through treatment, he was unemployed and I was supporting him.

Yesterday, we were talking about how his sister, who was recently diagnosed with breast cancer, was faring with getting insurance to approve various tests she needs to take so she can proceed with more intensive treatment. He told me that he would act as her attorney to represent her to her insurance company if she was presented with too many obstacles to getting approval for the tests she needs. In his words he ‘would make it his life’s mission to make sure they were bankrupt if they ever denied her anything’. I was struck by how motivated he seemed to be to do something for his sister, but when it came to me and him and our plans for our family, he was lackadaisical about doing anything. There was so much passion in his statement for his sister, but none for what I thought our goals were. It has me wondering if this is the right relationship for me.