Going through similar. WW seeming happpier then changes. Stop trying to read her. Just imagine it's something else cashing her mood swings. You don't need to know what - perhaps she saw a dead cat and it made her sad/cross. Perhaps it made her happpy. Stop trying to read her. If you try to read her you will follow her emotionally. Let all that go. Still means you care - but like a sister or a moody flat mate pay not mind, just think - ah there she is, looking moody/happy etc. Must have seen that dead cat again.
The idea will be something that fits her that she needs time to dress up as good for you. Pay no mind. She might even not have anything to say. For now. Pay no mind. It's certainly not very important or concrete as she would have raised it. She's prObably just going to tell you about that fecking cat!
It won't be better out of the M. It might be short term - there is short term relief from the 'pressure' for her. But long term she is still there (with 'her' problems) with an OM that is a cheat too.....just work on being super dad and forget about her as much a Humanly possible.
Take care. Keep going.
Surfer.
M46/W40/D8/S6/T20/M12/Separated 6/2016,W takes kids Issues2009 Wpartying w/g.f's2013on EA2013PAdeniedWleavesMBR ImeetAP/EAhalts VariousBDDates MFCourse WSpew EAresumes I halt Wrages DBIng4/2016