When it comes to dressing for someone else's wedding, there's usually one rule: Don't wear white. But when one needs to get dressed up for an iconic fashion designer's big day, there's also this unspoken rule: Don't you dare be boring. Well, Erika Girardi definitely got that memo when she pulled together her look for Marc Jacobs'  April 6 marriage to Char Defrancesco. 

For the big event, The Real Housewives of Beverly Hills singer opted for a short, ruffled, feathered, blue-and-green confection of a tulle dress. Or as Erika more succinctly labeled the pouffy look in an Instagram Story: "Cupcake walking."

Just look at this sweet and delicious ensemble, paired with icy blue heels:

And fittingly, her hairstyle that looked like a blonde cherry on top:

Sweet!