ITH very good mind set, you know that he flip flops so easily so it is best not to have too many hopes about this positive interaction (not yet anyway )
There is no point in trying to figure out the reason for his good mood, does it really matter? Just enjoy it!!! LoL
It is odd that he has not mentioned you not coming home but he might later no use dwelling on that either. You know that you have to go their on the weekend and you can just bring that up on Friday if it has not come up already by then.
)