Alcohol tolerance?

Me and my husband are both 29, I’m 5’8 & 270 lbs and he’s 6’2, 180 pounds. Obviously I’m a lot heavier than him, higher BMI, blah blah blah. I also used to drink a lot about a year ago. But as of recently, I only drink like once a week, or once every two weeks. But when we drink together, I can drink a bottle of wine and be relatively normal and he drinks not even a whole bottle and is pretty drunk.also to add, even though I’m heavy, I don’t eat a lot before drinking.
Why do I have such a higher tolerance? Is this a weight thing? Cuz I’m heavy? Or is there some other reason? Google got me wondering all types of things lol