Why do you leak breastmilk while having sex?

Oxytocin hormone. The hormone oxytocin is responsible for the milk let down reflex and is also released during an orgasm. Some couples really feel excited when this happens while others don’t feel comfortable with it at all. Moms can always wear a bra and breast pads during sex or can breastfeed baby before lovemaking. It is quite common for this to occur. Talk with your partner and have communication about it.