As a wise mainframe once said, the only winning move is not to play.
If she’s walking round with a face like a slapped arse, you ask her what’s wrong and she goes “fine,” react as though everything’s fine and get on with your day. Your relentless cheeriness will then either a) cheer her up too or b) piss her off so hard that she’ll tell(*) you what’s wrong anyway.
Life’s too short to be playing bloody mind games, the “well, if you don’t know what I’m thinking then I’m not telling you” game has no place in a grown adult’s brain. Share your problem with me, or don’t, but don’t be sitting there sulking at me like a child who can’t have any sweets just because I’ve not yet evolved telepathy.
The tricky bit is remembering that and sticking with it. It’s far easier to succumb to “aw honey, don’t be upset, I’m sure we can work something out, would you like a cup of tea?” (which is, after all, the purpose of the exercise), rather than “cool, if nothing’s wrong then I’m going to play Call of Duty for a bit.”
(* – scream)