Justin Timberlake is such a sweet husband. On Sunday, the singer posted a heartwarming tribute to his wife, Jessica Biel, on Instagram in honor of Mother's Day [2]. "I marvel at you," he wrote alongside a picture of Jessica walking on the beach with their 2-year-old son, Silas. "It's so hard to put into words EVERYTHING a Mother does. And, you do it with such grace. Thank you for giving me the greatest gift and continuing to show him what it means to be a good person in the world. You make me realize how much my own Mother has done for me. #HappyMothersDay to you, my love. And, to my wonderful Mother and all the Moms all over the world: Y'all really DO RUN THIS... I bow down to you. --JT" Of course, this isn't the first time Justin has won us over with his sweet tributes. Aside from giving us little sneak peeks of his family life [3] on social media, he recently wished Jessica a happy birthday [4] with an adorable note about how much he loves her [5]. Aww!