A. First of all, every woman is different. It's possible that chest action just doesn't do it for you, and that's totally normal. But if you want to amp up the sensation, try experimenting with different temperatures. You've no doubt noticed how your nipples become erect when it's chilly (that's due to small muscle contractions around your breasts - the same kind that cause goose bumps). Playing with cold temps, like having your guy use an ice cube to trace teasing circles around your nipples and along the sides of your breasts, can heighten sensitivity and increase your pleasure as a result.
Heat is also a titillation booster, since it brings more blood to the surface of the skin, making it more tender to the touch (in a really good way). To take advantage, ask your guy to alternate between licking your nipples and blowing on them with his warm breath.