As a man, I agree with (in no particular order):
aRLcat,
AMumInScotland
Anyfucker
Shiney
gagamama
SolidGoldBrass
ILoveTIFFANY
MamaLaz arou
(well, everyone, really - sorry if i missed you out)
and I feel so much better that the majority of women (at best) realise there's nothing to be scared of and join in, and (at very least) understand it's nothing against them or the relationship and no big deal.
(Ex is nightmare anyway, but had particular anti-wanking thing. Not anti-porn, just anti me wanking.)
May I also suggest another source reason for his porn use?
He may be somewhat unsure of, well, everything since the birth, and in need of some attention. Even if it's not your first child. It's often far easier to get negative attention by doing something you know will upset / annoy, than feel able to just ask for some positive attention.
Please. Don't be too hard on yourself, or on him. Especially if everything else is good.