Forget about reasoning with the girlfriend. It is just a recipe for extreme frustration. One way to diffuse her though (temporarily) is to question the "logic" of her many shoes, closet full of cloths that never get worn, multitude of shampoos and potions in the bathroom and other unusual things she likely has. She'll stop and think for just a second or two giving you enough time to run out and head to the flying field.

We all know you want more planes and I like your "justification" for it. Other new pilots take note; you might try using this one.

Have fun with the Corsair and the many, may more to come.

On a more serious note, keep in mind that the corsair is a fairly capable airplane. Make sure you apply what your instructor tells you to the Corsair as well.