Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
Shakespeare didn't name his play "The Bitter Wives of Windsor" or "The Vengeful Wives of Windsor." And there's a good reason for that. Even though Shakespeare explores some potentially weighty themes like "Jealousy" and "Love," the play is light-hearted and has a sense of humor (much like the title characters).
Sure, Falstaff is trying to tarnish the good names of two "honest" housewives and an insanely jealous husband runs around saying he wants to catch his wife cheating so he can "torture" her, but that stuff never actually happens. Hello, this play is a comedy, not a tragedy. At the end of the day, our "merry" wives teach both guys a lesson and all is forgiven. Nobody gets stabbed or strangled. Period.
Of course, you'll be needing an example of how Shakespeare turns male jealousy into something we can all laugh at. Try Act 4, scene 2, where Master Ford comes home and thinks he's going to find Falstaff hiding in a laundry basket. The guy goes absolutely berserk riffling through dirty laundry and beating the basket with a stick. But, instead of catching his wife with another man, Ford ends up looking like a "lunatic" in front of his wife and all his friends, and everyone has a big laugh. Check out this clip from a student production and you'll see what we're talking about.
Or, check out this film clip from Othello, where Iago tells a suspicious husband to strangle his wife "in her bed" (Othello, Act 4, scene 1). Unlike the male jealousy we find in Merry Wives, Othello's distrust of his wife is no laughing matter.