Which line from the play The Glass Menagerie leaves matters uncertain when Tom and his mother are together on the fire escape?

AMANDA: When he sees how lovely and sweet and pretty she is, he'll thank his lucky stars he was asked to dinner.

TOM: If you're going to make such a fuss, I'll call it off, I'll tell him not to come!

TOM: Aren't you being a little bit premature? Mr O'Connor has not yet appeared on the scene!

AMANDA A secret, huh? Well, I won't tell mine either. I will be just as mysterious as you.​