i used to be "OK" with it because i thought, if he's gonna do it, he'll do it without lying. it made me bitter and we went to couples counseling over it. turns out the professionals find porn to be very unhealthy in a relationship as well!
as a result of the counseling he installed a firewall and promised to stop for good. took a while to trust him, but I'm basically there.
having a baby is hard. no one should feel pressured to have sex just 4 weeks later.
it's normal to have a dry spell after a new born. if he's horny he can rub one out. you don't require porn for that.