Don't even have to pull the conversations then if you're just looking for evidence that it's occurring on the Mary Celeste as it's in the Codex -
As far as conversations, first, here's a re-quote of what I said for reference to show that what I said is true based on the evidence from the actual game that I am providing below: "the issue for some folks, though, is when the dialogue and codex has instances where the girls talk about taking monster dicks or sex with monsters is referenced despite the player not ever unlocking the related xeno scenes"
Here's a conversation the Captain has with Demi about Lily early on in the game even if the player doesn't unlock any xeno scenes:
Demi confirms this is happening "constantly".
And here's the Lily related chats indicating that her doing monsters in her past is canon. It's not something the player can opt out of at any point in the story.
So bottom line this isn't a debate. The facts are the facts.