Orgasm from Breast Stimulation

So me and my boyfriend were playing about with eachother and he was kissing my nipples and breasts, and I got that feeling.. like I could climax so I told him to keep going. Literally no stimulation down there whatsoever and I came so hard. Has this ever happened to anyone? Then he flipped me over and gave it to me and it felt like I was so much tighter from orgasming before even having anything enter me. The sex was good AF