I just suspect that they would be happier if far away from each other.

I actually think they'll be fine if they can get through Julian's mother-driven conviction of his essential unlovability and Hilary's Renault-driven conviction that she's Julian's starter relationship whose life's work will be to make him healthy enough to leave her! I didn't believe that entire passage about the Madonna of the Cave the first time I read it and I was in college! I know Renault believes it, but Renault believes a lot of hogwash! (Also the bit where Hilary resigns herself to the knowledge that the age difference means they can never have children, as a person whose mother was in her mid-thirties when she bore me and her late thirties for my brother, I call pffffft.)