What was Fuyuki mom talking about?

Seth7 said:
On the last episode when Fuyuki mom drops them at the school she tells Fuyuki "That was one fine play". Was she talking about giving Tsubasa a ride to school or about something else.

Kippershy said:
Personally I imagine it was for both the fact that Minami (assumedly) was the one who asked her mother to stop the car to pick up Tsubasa after noticing him, and for the flirting that she was doing.
Pretty simple, really. Mii was absolutely flirting and her mother was just playfully teasing/encouraging her.
It's hard to see past your own feelings when you're in that situation, so as a parent it's natural to either give guidance if necessary, or to say a subtle 'well done' if it's going well.