FTR, I nursed my DD1 until I weaned her (with love) when I was 6mos pregnant with DD2. My DH was fully behind me the whole time and was even ready for me to tandem nurse them both. I had never had a high sex drive and he was leery of me experiencing another bout of PPD, but did not at any time suggest that I wean. To be frank, if he did, he would've gotten a No from me. Period. The same as he did when his mother planted the seed of doubt in his head regarding our cosleeping. That was shut down with the quickness.
IMO, something else is at play for him but it's very easy and convenient for him to point to your BFing at being at the heart of the matter. Society condones his actions so it must be right, right? Wrong.