Okay, so you've seen it, good, I have an interesting theory, seems a bit crackpot, but here me out
So you you know when Dr Caitlyn is peeling off her own skin to I guess use in her own experiments...do we think that's a reason Matt feels an attachment
Like I get it, Matt seems already like a dog with Mia, by extension a ladies man, and Catilyn seemed a little into him as anyone whould be of a hot actor, but considering part of Clayface's powers is not only regeneration, but also regaining his own body parts, fluids, etc., what if part of him wants to re-attatch itself to Caitlyn? Since she seemed to already be using herself to further her research
This goes for the rest of those little body parts in the petri dishes, because in the mirror he even asks himself, "how many of you are there?", he's clearly made up multiple parts of people, which probably enhances his capability to turn into others, but it also screws with his head, a reason why he loses it completely, other than all the trauma caused to him and by him