This whole poem is just plain… flirty. It's all about how much the speaker enjoys his morning loving with his lady. Even the meandering imaginings have a flirtatious feeling, like "you could be doing anything, but you're here with me instead!" Wilbur even gets cheeky with some wordplay in the early stanzas, and then he finishes the poem off with a subtly sexy image.
Line 5: While the next line after this one reveals that Wilbur is talking about gardening, it's no coincidence that he breaks the line at "raucous bed." He slips that sexy image in at the very end so we readers have a split second to let our minds fall into the gutter before recovering them in the next line.
Lines 9–10: Who's boss? Even though Wilbur's talking about a dog here, if your mind happens to still be in the gutter, you might be able to see the sexual power dynamic between the lines. If you can't, then maybe you're too young; change the channel.
Line 12: This line should be read: "Isn't hanging out with me and smooching all morning better than just about anything?" The speaker has laid out an entire list of daily activities that he's pretty confident their love sesh has trumped.
Lines 19–20: It looks like they have something in common: kissing and cuddling are at the top of their "favorite pastimes" list.
Lines 25–28: This last stanza doesn't have the same flirty wordplay of the previous examples. This is some straight-up sensual and sexy imagery. The bracing acidity of the wine, the funk of the blue cheese, and the saltiness of the crackers stimulate the senses, like, say, a good kissing session might. The final line, "ruddy-skinned pears" is maybe the most overtly sexual image: it looks a whole lot like (gasp!) a nude woman.