I'm not suggesting our hypothetical man hadn't tried contraception. Contraception is not foolproof, neither for disease nor for pregnancy. Apparently it shouldn't matter?
Remember what this post-feminist society of ours has supposedly taught us: that women want sex too, just as much as men do. Oh yeah, and men also get raped by women far more often than gets reported.
Take the above points together, and you could argue the woman should have been responsible enough to take the pill before consenting to (asking for) sexual play.