Impressive stuff. I've been reading this off and on over the past few weeks, and it rarely disappoints. 

There's too many parts to praise. I like how the relationships evolve. I like that all the girls seem to like being huge. Eve and Lilith are fun in a genre where the kinda-omnis tend to be boring. Honestly, I like that Lilith isn't piss-evil for the sake of it, just...not caring about others as much as she ought to. She doesn't feel irredeemable, however much she ought to be.

About the only complaint I can give is the abundance of rooms that grow. It's not really giantess sex when the surroundings are also gigantic, you know? Makes sense in an in-world narrative way, but still takes some impact from the scene.

All in all, excellent work.