Starting the letter with, "when we met you were 19, today you are 29... I thought I could share some of my favourite things about my favourite dude in honour of this very special day."
Adorably, the Last Song star revealed, "I love your dirty socks on the floor cause that means you're home."
"I love going to a random to a random party and remembering basically everyone is fake AF out here and how lucky I am to share a life with someone real."
While there are so many classic romantic lines, the best takeaway might just be, "I love having a teeth brushin' partner and when I'm lazy how you'll comb my hair.
"I even love when you shrink my favourite t-shirt in the dryer - because have a boyfriend (oh em gee I almost forgot you're my friggen husband now.)"
Could Liam and Miley be any sweeter? We can't wait to find out what else 2019 has in store for this A-List couple!