How to approach this subject?

I've been skinny all my life, I hit 30 and got on the pill and got a great shape. Now, aftee the baby I just wanna lose at least another 10lbs and I'm happy. You see, my fiancée is a bodybuilding fanatic, sometimes he shows me pictures of women who are on these forums how they transformed after having a baby. It's a matter of taste, and I don't like excessive muscles especially on women besides the amount of steroids and all the other junk they take, it's a lifestyle. I prefer a feminine body with delicate features. He knows this and I'm starting to get really annoyed at him for this, it's almost as if he is silently telling me "this is what you should be"

Not sure if I'm being sensitive because I know my weak points in my body for now, but in a way I want to confront him without being a bitch about it.