Because looking at photos of young Ryan Phillippe and teenage Eva Mendes never gets old

By Jessica Fecteau
Updated April 10, 2015 06:35 PM
Credit: Vincent Sandoval/WireImage

Oh, brotherly love.

Friday is National Sibling Day (yep, it’s a real thing), and not only did it probably take over your Facebook news feed today, it took over Instagram, too, thanks in part to several stars who made the “holiday” an opportunity to share seriously adorable throwback pics with their beloved brothers and sisters.

From a young Ryan Phillippe and baby Brooklyn Decker to an adorable Eva Mendes and (naturally) gorgeous Cindy Crawford, enjoy f-aww-ning over some of the best photos we found today. //

PEOPLE Hangs with Two of Our Favorite Brothers