My DH went to an amazing breastfeeding for dads session run by our local NCT breastfeeding counsellor. It was run by the lady and her husband, and I absolutely credit this class as the thing that kept us going with breastfeeding as a family. My DH has always been so supportive, bringing drinks and snacks in the early days, bringing the baby to me for night feeds and helping me adjust my latch.
The local NHS breastfeeding classes are advertised as "strictly women only"
I personally have no issue with how a woman chooses to feed her child, as long as that child is happy and fed. I do have an issue with women not being supported in their choices, and it's hard to be supported when breast feeding is treated like some daft secret society.