https://www.reddit.com/r/loseit/
A community for weight-loss, primarily by means of inducing a caloric deficit.
You said it yourself, he is taller, fatter and has more muscle mass. Of course he has to eat more than you because he also burns more calories than you.
If you would eat till you are full, and he would eat the same amount, he would still need more. And not because he's a fatty fatty fatso but because more mass needs more calories.
You’re reminding me of a few larger women in my life who have said, when I talk about how quickly I’ve lost weight with intermittent fasting, something along the lines of “how easy men have it with weight loss.”
It isn’t just the numbers on the calorie calculator that scale with size and biological sex. It’s also the hunger, because those are the basic needs. You need to be hungry to lose weight, and I’ll lose weight while eating more food than my wife because my very existence burns more calories, but I’m fighting the same hunger.
I get annoyed at people who won’t try not because they’d have it easy, but because they would rather complain about their lives than do something about it.
It is a little annoying to see the volume of food they can eat but it's always going to be annoying. I'm a little taller than average so my maintenance is closer to 2100 at the moment but I still look at my brother needing 2700 and get jealous. At the end of the day you'd both be hungry eating under your maintenance.
Maybe it helps to think about the fact that everything scales with size so while his target kcal for weight loss might make you fill full (or maintenance) but for him it might be as challenging as your 1200 kcal limit.
Overall all you can do is do your thing, potentially introduce healthier habits like substituting rice with chick peas etc. but eventually he is responsible for his body. (I am also responsible for my weight gain).