When people tell us to act our age it usually means they are uncomfortable with our behavior and want to shame us into stopping it. If we are doing something that is wrong, we should stop it. But if we're doing something that is not hurting anybody and people simply don't like that we are doing it, that's their problem and we shouldn't feel the need to change who we are. We should be authentic. People always have the choice to not hang out with us if our behavior makes them uncomfortable.