He can't even begin to answer that without giving away something vital. No, he must not even imply that there's another event he's planning to stay for. That would upend things completely. He really shouldn't have told her at all, but given how he can't undo that decision ...

No. He just shakes his head. "They haven't disinherited me," he says, completely skipping her other question. "They never would, no matter what I do. And my brother does not want my seat."

Poor, poor Mark. He suffers the most in this scenario.