cherrios

I think it was both Eliott being burned or shy about the stuff that Lucille used to do in a way to "manage" him and that's ingrained in him, so he doesn't want to repeat that with Lucas. So Eliott keeps mum about certain things because he doesn't want Lucas to be Lucille 2.0. But also Eliott's fear and insecurities that he in every part of who he is, that it would cause Lucas to pull back and that Eliott would lose Lucas as well. Something that Eliott doesn't want to happen.

But also it's somewhat true to Eliott, (not to this extent, but it's tv) he's used to be a solitary character that handles things on his own. That keeps a lot of things locked up inside, which I think it something that Lucas does as well. Which makes sense considering Lucas's background and his relationship with his parents. And keeping things secret and private from Lucas. Like Lucille, Eliott's relationship with Lucille, Eliott's MI, Eliott's past issues, Eliott's relationship with Idriss, etc. And Lucas has repeatedly wanted Eliott to be honest with him and to communicate about things.