There is a pretty big difference between having it done out of necessity and waking up to a grown man drinking your breast milk. In this case, yes, it is creepy, wrong, and disturbing. How would you feel if you were in OP's position? It doesn't matter if he's her boyfriend or the father of her kid, I think it's safe to say she felt violated.

I will keep my personal feelings on the matter to myself so as not to be chased through town with pitchforks.

I doubt they got men to breast feed from engorged women, if you are breastfeeding a kid you do not get sore breast because it is drunk by the baby. Your breasts only become engorged to the point of pain if you cannot beastfeed but can make milk, letting someone feed off you or forcibly expressing the milk just prolongs the situation in that case. I couldn't breastfeed and ended up with cannonball breasts, very painful. I asked the health visitor if i could express the milk for my son since he could still drink milk he just couldn't latch on. She said no because I wouldn't be able to express enough by hand or by pump and it would just hurt me more. My friends that do breast feed have never mentioned painful breasts because of too much milk.