My girlfriend has a technique she uses that is pretty erotic but I'm not sure if it has its intended effect. When my penis is hard, she caresses the underside of the head and the entire shaft gently with a soft material or finger, and she nudges its head, not letting me move or flex my penis at all, though it just about raises up or twitches on its own. Not letting it move is hard, and makes me have this sensation in my balls and groin that is frustrating but nice, but the urge is to flex my cock so as to let the feeling flow. It is like being teased. My girlfriend seems convinced that this will help my premature ejaculation. She even whispers in my ear that I'm going to get a spanking if my cock doesn't stay still. But that is extra. We'll see if it works.
Some of premature ejaculation can be mind over matter -and that is the premise your girlfriend is working on. If your ejaculation is just sooner than you wish it was and not real cllinical premature ejaculation - it could work.
And those whispers in your ear are just the mildest form of erotic power exchange - and for some that will also work. If you are enjoying it - go for it- won't do you any harm.