I feel as though this is 50% Doctor/Donna and 50% real-life Tate/Tennant adlib. And 10′s valley-girl “yeah!” is just…I want to hug him. That is all.
How comforting and wonderful that all she has to do is say, “Spaceman,” and he knows they’re still on good terms and their friendship hasn’t spoiled. His little corner-of-the-mouth smile is such a lovely giveaway that he knows exactly how she feels about him despite her annoyance. This is my definition of true friendship: You can get frustrated with one another, but your affection is never in doubt.
Donna makes a brilliant observation and 10 is just beaming. Empirical evidence that the Doctor celebrates and is gloriously proud of the strong, intelligent women in his (soon to be her!) life. A+ feminist ally support, 10.