Lying for my partner and prom hardships (vent? Kinda long text)

I ( Cis-F) and my partner (FTM) are both 18 and excited about prom, however there are things in the way of us enjoying this moment we didn't expected. He's not out with his family and ofc they do not know we are dating but we are rather "friends". On the other hand he's out with my whole family and is well accepted. We wanted to go tgt to prom but didn't consider that if his parents (one or both) went we wouldn't be able to live the night as partners, he wouldn't be able to wear a suit (and other stuff like that) and that them allowing him to go alone with my family would still be complicated.

We got my parents involved to try and convince his but we had to lie to them in the process so he could go alone (since we have a close bond in the family it feels strange to do this, even more so watching my parents do it for him) bc his parents were really persistent on going. I love him wholeheartedly and would do everything for his happiness, wellness, etc. Yet I feel kinda guilty about getting my parents involved like this (they srsly do not like lying), about us having to missgender him while talking to his parents so he doesn't have problems at home, this all feels a bit overwhelming cause his gender identity shouldn't make it so hard to live something as simple as prom, rn it feels unfair.

My mom tells us to go regardless of his parents going but just hearing his parents talk about him made me sick and I wouldn't bear it for a night, even less if I had to missgender him or talk about him like someone he is literally not, about having to keep on lying about lots of things like him coming over to my house, having a good relationship with my parents, about where we go every afternoon he gets late to his house (they know he stays with me), of my parents having to get along with his even if they don't like them one bit. The worst part is that this all story makes it impossible from him to come see me before prom so that day is all or nothing (prob. Nothing).

I wish his parents weren't awful and we could just enjoy this peacefully.