Honestly, who WOULDN'T give a love note for Cara Santana and Olivia Culpo?! This super-sexy duo went shopping together on Tuesday in matching white ensembles, looking like a walking Revolve advertisement ... and when they returned to Cara's car, there was a love note waiting on the windshield! We never found out what it said or who wrote it, other than that it was signed by "The Milk Guy." The Milk Guy?!

On to more important things ... Cara took to Instagram for a good cause yesterday, to promote #ElPasoChallenge. We all know what happened there the other day and now a 11-year-old is challenging people to do good. Here's what Cara wrote ... and check out her Insta-video: "An 11 year old in #ElPaso challenged everyone in the city to 22 acts of kindness in honor of the 22 lives lost this weekend. I took that challenge {you can follow along on stories} and I challenge all of you to at least 1 act of kindness and love for the lives taken in El Paso and in Dayton this weekend. #ElPasoStrong #ElPasoChallenge