You may be my brother-in-law on paper, but you’ll always be a true brother to me at heart. Happy birthday!
Brother-in-law, I am wishing you all the happiness possible on your birthday this year! Have a great birthday!
You’re a big part of this family and an even bigger part of my heart! Wishing you the best on your birthday,...
Happy birthday, brother-in-law! On your special day, I hope I can make you as happy as you make everyone else!
I didn’t just gain a brother-in-law in you, I gained a true brother. Happy birthday to you, bro.