Ummmm

My fiance is 11 years older than me, I’m 22 he’s 33 (our birthdays are 5 days apart so it’s an exact 11 year difference). I’ve noticed that lately he’s becoming more aware of his age, over this last weekend we went out drinking and I made a joke about how he’s not 22 and can’t drink like me anymore, usually he’d laugh it off, but that night it kinda got to him, he didn’t get mad or upset, he just didn’t take it as lightly as he usually would’ve, then last night when we were in bed he said “babe, I’ll be 34 this year” I was like okay? And I’ll be 23 Lol then he said “that doesn’t bother you?” I was just like no? Why would it? And I reassured him he’s still young. This man is literally so young and full of life, so much fun to be around, yet mature and responsible, not your average 33 year old. What can I do to help him out here? I figured this would eventually happen but i didn’t expect it to happen until much later because to me 33 really is still young