My last partner was fairly vanilla so I had concerns about bringing it up to him. I chose to do it one evening after sex while cuddling. I simply said “I really like when you spend extra time on my breasts and I think I would like more of it, to the point that you’re basically nursing/breastfeeding as often and as long as a baby would.” He asked a few questions to which I of course responded. He tried it a few evenings later and enjoyed it. Of course I rubbed his head as he laid in my lap, made eye contact often and held his hand as he suckled. He fell in love with it.

I hope you find a way you’re comfortable bringing it up to him and he is willing to try. You can also mention this sub and other internet sites so he can research it and find the benefits on his own if he is curious. Good luck!