Should my character be 21-23?

I’m writing an R-rated superhero story. My main character gets his powers from chemicals. His boyfriend, who’s older than him (maybe 6-14 years older), is murdered, and he brings his killers to justice. My main character is bisexual, and most of his love interests are 6 to 14 years older than him—maybe some even older. His best friends are in their 20s and slightly older than him too.

Should he be 21 at his “year one” start and 23 be the “year two” part of the story? That way he’s an adult, but he’s still young enough to have that youthful “young” vibe.

If he were 15-16, it wouldn’t work, mainly because, like I said, his friends and love interests are adults who are older than him, and he’s a vigilante whose whole thing is “justice”. That line would get skewed if his love interests were, you know, committing a crime just by being with him, and his adult friends would look complicit and not heroic for allowing it to happen.

If my character is 21-23, while it might be “weird” for him to date older men and women, the older partners don’t deserve to die for being with him, and they aren’t committing a crime because he is a consenting adult, and consenting adults have free will, so him fighting for “justice” won’t get blurry. What do you think?