Wilbur opens with the "what if" game, that is: the hypothetical. Our speaker is daydreaming about what his lover could be doing at the moment, but chooses not to. His daydream drifts from the library, to the mall, out to the garden, over to a dog training session, and then into academia. Finally he pops back into reality to remark on the fact that his lover isn't doing any of those things; she's just chilling with him instead.
They're in bed smooching, it's nearly noon, and they've been there all morning. It doesn't really seem like either of them will be straying far, either. The one attempt at change comes near the end of the poem, when he asks his lover to stay a while before heading downstairs, not to leave, but to grab some grub so they can continue their lazy, loving afternoon together. How sweet!