Hold onto your hats.
Noir’s Kentucky Derby Clubhouse Party
What: Chapeau yourself for the big-screened race while snacking on Southern vittles ($5) and carousing with mint julep-inspired sips ($8-$12).
Why: Pull out the seersucker to score prizes for best-dressed belle and gentleman (and, of course, best topper).
When: Sat., 4-8 p.m.
Where: 1 Bennett St., Harvard Square (617-661-8010). R.S.V.P. to email@example.com.
Patch NYC’s Expansion
What: Prance into the larger, gallerylike space to peruse tons of new offerings, including Klein Reid home accessories, Astier de Villatte ceramics, and vintage glass vessels.
Why: They love you, too. Get 20 percent off jewelry and scarves thru May 6.
When: Tues.-Sat., noon-6 p.m.
Where: Courtyard at 46 Waltham St., 46 Waltham St., South End (917-292-2640).
Cinco de Mayo Flash Mob
What: Congregate at Papagayo, then set out for a mystery locale (within a half-mile of the restaurant, heel-wearers!) guaranteed to include mariachi, guac ’n’ chips, and Coronas and margaritas aplenty.
Why: A sabado fall-on date deserves a proper fiesta.
When: Sat., 1-4 p.m., 5-8 p.m., or 9 p.m.-midnight.
Where: Meet at 283 Summer St., Fort Point (617-423-1000). Tickets ($30) online at eventbrite.com.
MFA First Friday: Beach Party
What: Put on your finest cotton frock and start the warm-weather carousing with a summer-themed bash in honor of the new Alex Katz Prints exhibit.
Why: Drink a passion fruit margarita, the first of the season’s many.
When: Fri., 5:30-9:30 p.m.
Where: Museum of Fine Arts, Shapiro Family Courtyard, 465 Huntington Ave., The Fenway (617-267-9300). Free with museum admission ($22).
Muddy Paws for a Cause
What: You spring-cleaned the house, now tackle your messy mongrel during a weeklong wash-a-thon benefiting the pooches at MSPCA-Angell ($20).
Why: Fido’s got a winter’s worth of filth.
When: Sun.-May 12. Mon.-Fri., 7 a.m.-8 p.m.; Sat., 9 a.m.-6 p.m.; Sun., 11 a.m.-5 p.m.
Where: Bark Place, 1721 Washington St., South End (857-362-7494).
Photo: Danielle Scott / Flickr