and Lucas has some pretty sick mommy thoughts.
This, 100%.
Lucas's habit of describing his female family members as "gorgeous", (and his intonations give the word a very wet, lustful, heavy-breathing quality) extends to his mom. As Bermuda has reminded us, Lucas's mom was the pattern, the forerunner for the smart pretty interesting girl that Lucas sought for the rest of his life, unsuccessfully. Lucas has described both his blood mother, and his stepmother in terms that one generally wouldn't expect a son to describe their mother with.
I don't think Lucas is likely to physically commit incest with his mother, obviously distance and reality make that unlikely, but I think Lucas has the same sort of unhealthy psychological attachment to the concept a "sexual mommy" figure, which he got from his mother.
He sees nothing wrong with telling the world at Large: "what good are girls to him, if they can't even feed him and comfort him like his mother?" He doesn't realize how this sort of comparison shows him to be the arrested infant that he is, and most girls wouldn't want to enter into the oedipal nightmare that such a relationship would necessarily be. One of the most interesting things about Lucas, to me, is how he says these sorts of things, then seems to momentarily realize how horrible they sound, and say he's not expecting a woman to mother him, and that he would take care of the woman because of how well his mom raised him, but.... he's still unable to stop himself from making that sort of comparison. He does have some residue of a social conscience, however minute, it's just massively drowned out by all of his lusting, gorging, rutting impulses.
So yes, physically I don't think it would happen, but psychologically, I think Lucas and Chris are coming from a very similar position.
Changing the subject a bit, I've been thinking a lot about how someone in a therapy setting would approach fixing lucas, and trying to compare where he ended up before this recent hospitalization compared to when he came out of his longest therapy that we know of.
Lucas, in the past few months before he disappeared, had commented on how good anger was, and how useful the anger impulse was as an impetus for energy.
When he was fat and sedated, and he had just come out of hospital, the therapist had managed to internalize the idea within Lucas that his anger was something to struggle against, but anger is such a big part of lucas, and it's connected with his mania, the "high" part of his bipolar cycle, that I think separating him from these concepts is the first part of detuning his freak-out reflex.
I imagine this would be quite difficult, because Lucas repeats ideas to himself, to others, and to no one at all, until he makes them reality. In this way he's very similar to Chris: he repeats the reality of the world the way it makes him the least culpable for his negative situation, and drills it into his own head until it becomes his everyday reality. In this sense, he stirs up his own anger, because I imagine he, probably correctly, realizes that anger is preferable to sadness and shame.