Irene's response makes Claire pause. There seems to be an implication behind her words. At the realization, Claire relaxes.
After all, Marcellus just broke up with Katrina. He is drunk and fragile. If Irene takes care of him tonight, he might see her in a new light.
Claire is also an adult. She knows the possibilities and consequences of letting Irene stay and take care of Marcellus.
She has been rooting for Irene for a long time. This would be a good opportunity for them to develop their relationship. Hopefully, after tonight, Marcellus will finally end up with Irene.
With that in mind, Claire doesn't feel guilty about manipulating Marcellus at all. She nods quickly in assent. "Thank you. I'm sorry to bother you like this," she says, hastily leaving to give them some privacy.
After Claire leaves, Irene makes her way to Marcellus's room.
That night, Marcellus dreams that Katrina gets back together with him.
