What was Big Willy Shakes going for?
As we know, Falstaff is interested in getting two things from our "merry wives": (1) money and (2) sex. It turns out that Shakespeare uses some pretty colorful metaphors to show us that Falstaff is seriously sleazy when it comes to trying to hook up with these women. Not only does he write them super cheesy love notes, he's also got a way with words… not.
Here, he can't get enough of using animals or, weirdly enough, food, to talk about sex. More importantly, we think this passage says a whole lot about Falstaff's personality. Falstaff talks about food when he's feeling romantic because he's got a huge appetite for everything the world has to offer. In other words, his love of food and drink and sex is emblematic of his zest for life.
When Falstaff isn't eating and drinking in this play, he's talking about eating and drinking. Seriously. It seems like he's always on a barstool ordering someone to "Go fetch [him] a quart of sack" with a piece of "toast in it" (3.5.3). The first time we see him in this play he's over at the Page's house getting ready to grub down on some tasty "venison pasty," a.k.a. Bambi pot pie (1.1).
At one point, he even says he's afraid a fairy might turn him into a piece of "cheese" (5.5.79). It's the same with animals. Falstaff makes a bunch of really obvious deer puns to let the ladies know he's ready to mate. We told you he was cheesy.
Falstaff assumes the gods are in on it with him. He figures they're really "hot-blooded" or passionate in their own love lives, and he hopes they'll help him out with the ladies that night in the park. He even fancies himself a god. (Can you believe this guy?) Falstaff thinks he's just like Jove, and hopefully can take the ladies since he's got such an appetite for lust (and everything else).
What's our point? Well, we think Shakespeare is trying to tell us something about his larger than life guy. Here's what his message boils down to: unoriginal and uninspired love notes or dirty puns are like casual sex. Guys like Falstaff might think it's fun for a while but, in the end, it's empty and meaningless. And smart ladies know better.
It's not just sleazy wannabe players who use this line. King Lear describes someone as hot-blooded in his own play. Once Shakespeare coined it, he wanted to use it again.