<human>: My fiance and I have been together four+ years. We have lived together for three of these years and we're planning a wedding for May of 2014.

He recently came down with an illness that actually caused him to go see a doctor (he NEVER goes to the doctor), and I refused to pay for it because I have excellent health insurance and he should become a domestic partner now that we're engaged, so he could at least reap the benefits of my health coverage before we get married.

His mom offered to pay for it (i LOVE her, we get along fabulously) but she took my side and said that we should become domestic partners and that she would even pay me the difference that would come out of my paycheck as long as he had health insurance. She's a smart lady.

The problem... He says this... "I'll just wait till the wedding. I'll be fine."
He seems to be completely anti-domestic partnership. He proposed in March and he's been all about the wedding planning (which I, ironically, have not been... I have a severe anxiety problem and every time I think about planning it I have an anxiety attack). Anyway, I have no intention of leaving him and we have no other problems in our relationship (other than the typical occasional bickering here and there but nothing too serious).

So, my question to you relationship experts... is this a big deal?
I just want him to be healthy and this last thing kind of scared me, besides being expensive for his mom to pay for, it made me nervous that a) he was sick! :( and b) he didn't seem to care enough about what both me and his mom wanted for him (with no out-of-pocket cost to him,... all he would have to do is fill out some papers).

Could you distill the essence of the text into 1-3 sentences?
<bot>: fiance doesn't have health insurance, he got sick, it was expensive, and he STILL doesn't want to be domestic partners so he could be covered under my health plan.