Good luck my friend...hopefully this relationship can continue and blossom to the advantage of both of you. With or without the lactation.
ANR (adult nursing relationship) is pretty rare, sort of like cumditioning of hair. I knew one girl who got orgasms from her breast pump, she said it was better than her Hitachi vibrator. She would take off lunch at work, go to the women's bathroom, and put on the suction. She had really big breasts (44G bra) and could easily do a liter per day. She had a boyfriend who was into it, and what he didn't drink she donated to a breast milk bank in town which was generous too. I always fantasized about what it would be like to suck on those two big melons.....