Do you think it's more about pressure to perform than it being too "real" and perhaps feeling used from his end too?
(ok, hear me out...)

When we were ttc dh commented that it's be nice to have sex just for the sake of having sex. Not having to worry about the right timing, temps, ewcm and hanging upside down from the bed head to make sure it all gets in there He felt like I was just using him for his sperm and not because I "wanted" him.

Ttc is hard, really hard but I hope it happens soon for you both xx