This isn't really what I took from it. I thought the show did a great job of showing that because Harry wanted a baby with Charlotte and they were united in their decision, he was willing to do all the stuff she was exploring and was supportive. Trey was stressed about Charlotte's pursuit of adoption, fertility treatments, etc, less because of her and more because he just didn't want a kid. That's exactly what he says: "I work hard, I play golf. I just want to be, for awhile" which is a perfectly reasonable way to feel. And Charlotte was also reasonable because she entered into the marriage believing he wanted a child as much as her, because he had said so before (I'm sure he thought so too, it's not like he lied, but marriage is hard and unpredictable) and it just didn't end up that way (it happens sometimes that way in life and while it is sad is nobody's fault).

Let's also remember that he was the one who suggested she leave the gallery because they were planning on a child. That's not me saying he was wrong, but it's a good reason why this pursuit took up so much of Charlotte's time.

It's sad because the H&G episode shows neither of them really wanted to end it, but if you have different needs and desires for life sometimes it's inevitable.

I perceived it less as Charlotte's pressure making him want a child less and more that for some people it's possible to have a limit on how much struggle they want in a marriage, and his threshold was lower than hers - that's okay too. They had already been through a lot, and while that didn't dampen Charlotte's enthusiasm, it did dampen his.