She's a little bit country, he's a little bit rock and roll
A reference to either Donny or Marie (or both) Osmond(s), specifically their hit Little Bit Country, Little Bit Rock n Roll.
The Osmonds are a semi-frequent reference point on Wittertainment. Not just because of their occasional acting roles (Donny was in College Road Trip, a film not even the Good Lady Ceramicist Her Indoors could praise, and she was in the Donny Osmond fan club). Orloondo Bland, for example, is the Donny Osmond of his generation, only without the teeth, or indeed the talent.