It is a truth universally acknowledged that on your birthday, your best friend must post a cheesy, heartfelt photo collage dedicated to you on Instagram. Thankfully for the members of Taylor Swift's squad, the megastar and fashion designer is well aware of this rule and posted an adorable message for her pal and "Bad Blood" video alum Lily Aldridge's 30th birthday. The post is full of sweet snapshots of the friends holding Lily's daughter, Dixie Pearl Followill, followed by the caption: "Happy birthday to a mommy who lets her little girl dress like a princess whenever she wants, and makes balancing a million things look effortless and fun. I'm so glad you invited me to a Kings of Leon concert 6 years ago. My life would be unrecognizable without you, @lilyaldridge."