Popsugar Celebrity Outlander Caitriona Balfe's Birthday Posts to Sam Heughan 2018 Caitriona Balfe Is Trolling Sam Heughan For His Birthday, and We Can't Get Enough 3 May 2018 by Kelsie Gibson First Published: 30 April 2018 Twitter just asked what’s happening.. and I can safely say I have no idea!!! Happy Birthday our kid @SamHeughan pic.twitter.com/bx520mZ6Tz— Caitriona Balfe (@caitrionambalfe) April 30, 2018 Caitriona Balfe and Sam Heughan's characters have an epic romance on Outlander, but off screen, the two have an epic friendship. Case in point: Caitriona's recent birthday messages to Sam. In honour of the Scottish actor's 38th birthday, Caitriona decided to completely troll her costar by posting a number of hilarious photos on Instagram. "Happy Birthday darling!!!" she wrote alongside a photo of Sam photoshopped on her body. "May you feel like a princess alllllll day 😘😘 @SamHeughan 👸🏻👸🏻👸🏼👸🏼." And that's just the icing on the cake . . . pun intended. See the hilarious messages ahead, and then see which other lucky celebrities are part of Sam's inner circle. Who da best ..????? Always pamper yourself on your birthday. Especially if you’ve just crushed a marathon!!! @SamHeughan #ipromisei’llstopnow pic.twitter.com/7L44GdkupN— Caitriona Balfe (@caitrionambalfe) April 30, 2018 1 / 5 That way to old age.???? Sure sharky!!! @SamHeughan #birthdayboy pic.twitter.com/3RKtDSlkLN— Caitriona Balfe (@caitrionambalfe) April 30, 2018 2 / 5 It’s your birthday....!!!!!!!!! 💃🏻🕺🏿💃🏻🕺🏿💃🏻🕺🏿 @SamHeughan pic.twitter.com/cJMLKWJRT5— Caitriona Balfe (@caitrionambalfe) April 30, 2018 3 / 5 Arghhhhhhhhh it’s your birthday !!!! @SamHeughan 🍾🍾🎂🎂 pic.twitter.com/eyP8nEDeoz— Caitriona Balfe (@caitrionambalfe) April 30, 2018 4 / 5 Twitter just asked what’s happening.. and I can safely say I have no idea!!! Happy Birthday our kid @SamHeughan pic.twitter.com/bx520mZ6Tz— Caitriona Balfe (@caitrionambalfe) April 30, 2018 5 / 5 OutlanderCelebrity FriendshipsCaitriona BalfeSam Heughan