Well, let's suppose he wanted her to have the baby, but she didn't want to have it. Is she supposed to have to go through with the pregnancy (and believe me that was a lot bigger deal back then that it is now) and flush her career just because he wanted her to do it? I don't see him claiming he offered to marry her. He just wanted nature to take it's course which is great when nature taking its course didn't affect him at all physically, financially, or professionally. She's the one who was going to bear ALL of the bad consequences, and he was not going to have any bad consequences.
And then he's upset because she turns cold when he basically says he wants to back off the relationship? Yeah. What did he want her to do? Sob and beg him? She's got her pride too.
as reasonable and smart as always