Question: I am 18 and my girlfriend is 17. She likes it when I squeeze her breasts during oral sex. My question is why does a little bit of milky substance come out of the nipple? It only happens on one of them and it is barely any. What is it? What does it mean?
Answer: It is probably normal and not a reason for concern given the circumstances.
Please see the information at the links shown below.
http://www.mayoclinic.com/invoke.cfm?id=WO00093