Attaching Really! Wouldn't miss a moment what with funeral girl thinking of making a move on your H, and you looking sexy in the oranges isle, why watch TV?
Two things, your MIL not knowing how to show her love, I think you're totally right about that. But she also seems to have a little catty side, which likes to poke and hurt at times. Like the mug business, or mentioning your H's girlfriend in front of you. I wonder where that stems from, maybe jealousy, or maybe she's hurting so she needs to hurt you back. You're the therapist so you would know better. But your MIL sounds a little like my sister.
Your H not sleeping in a bed in your house might be because he's scared to. Either of giving you the impression that he is comfortable at home and then you might think he's coming right back on a white stallion with 100 red roses, or because he's scared of admitting it to himself. So he makes an outward point of not being at home. The couch is where teenage friends stay over.