Birthdays are an incredible opportunity to celebrate those you love. Check out these happy birthday son-in-law messages that ...

Happy birthday, brother-in-law! When you blow out your candles, ... Birthday blessings to you, brother. My prayer is that you ...

Birthday wishes for your brother-in-law. Happy birthday to the only person I would have allowed to marry my sister/brother. Happy birthday! I’m so glad you married [sibling], ...

Happy birthday to the best person my brother/sister has ever introduced me to. Feeling extra lucky to call you sister on your birthday. Happy birthday to the best sister-in-law a gal could ask for.