I echo Kira on this. I have had a fixation with my breasts for ages (largely because they are what you might describe as tiny). I used to play with my nipples when younger a lot and have always asked my lovers to indulge me. I like my nipples sucked, tweaked, pinched, licked, pinched - you name it - I like it. I get intense pleasure from having my nipples played with and that is not just the sense of love and enjoyment that I get, but translates directly into my vagina. the more foreplay I get, the wetter I get. And the more aroused I get - as far as orgasm. It is not only the nipple stimulation that makes me cum. Everything has to be right. But the attention to my nipples is ahuge part of the pleasure.
My favourite foreplay is when i am in bed with my lover and she uses her finger and mouth to manipulate my nipples through the lace top of my nightie. It is exquiste to feel the sofness of her mouth and the roughness of the lace at the same time.