Question: My girlfriend doesn't find nipple stimulation pleasant, in fact nothing other than me going down arouses her. Can you give me some advice?

Answer: Only 50% of women find their breasts sensitive to sexual stimulation. Her responding only to oral stimulation of her vulva is normal. This simply means her vulva and clitoris are more sensitive to sexual stimulation. This is true for many women. You probably prefer to have your penis stimulated and she likely prefers to have her clitoris stimulated.

If you like to touch and stimulate her breasts with your hands and mouth then ask her permission to do so. Even if she does not enjoy it from a physical standpoint, she may like that you do.