Oh dear. This is really sad. People's sex lives are their own business, but when they are posted on mumsnet then presumably it's ok to comment..esp. in AIBU
So.....the idea that a man would choose to put his sexual preferences above the nutritional and health needs of a tiny baby, his tiny baby, is really sad, and possibly unfair to many (most?) men.
Breasts do tend to leak at first (not with established bf) during sex, but if that's an issue women can keep their bra on and just use breasts during sex through the fabric (I don't have to spell it out for people, do I?). It's a bit different, some people may think the effect is not worthwhile, but FFS, it's not gonna kill anyone to do something a bit different for a few weeks. Or you can have sex after bf, when leakage is less likely.
Feel sorry for men if you want to, think they are being 'deprived', fine....but whose needs should come first, if there is some competition? A new baby's, or a grown up adult man's?
If a man goes off a woman because she breastfeeds, then what sort of a man is he?
And for the record, it's pregnancy that changes the breasts, not breastfeeding. Breasts return, more or less, to what they were before, in most cases, given time.