I don’t know the scientific or psychological reason, but yes: it’s the same for me.
I don’t have to get a stiff member unless it is caused by my wife. Very simple rule.
This is of course enforced by means of a chastity cage. As soon as my wife dominates me, I bow to her power, I become sexually aroused and my penis swells. No matter whether the situation is sexual in nature or just an everyday situation.
In everyday life, when I’m dressed, she doesn’t always notice my erection immediately because of the cage. She then grabs my crotch to feel how tense the cage is.
In any case, she always goes for the erection. She then scolds me, laughs at me, punishes me or teases me, depending on why the little one got stiff.
In any case, she enjoys being able to see the effect of her actions on my erection 🙂