Earl and his wife, Nina, were involved in a crazy incident back on April 13 ... one in which Nina was accused of holding the ex-Ravens safety at gunpoint.

The story was insane ... cops say Nina admitted to aiming a loaded gun at the football player's head after she allegedly caught him cheating.

Nina was eventually arrested ... and her case is still playing out in the court system.

But, seems all has been forgiven in the Thomas household ... 'cause the 3-time All-Pro gushed about Nina in a social media post Friday for her 31st birthday.

"Just want to take the time to wish the woman who I can talk to in the middle of the night ... who has accepted who i am through it all and has helped me grow in so many ways," Earl wrote.

"I hope you enjoy what I’ve planned for you bae.... 31 is going to be your best year yet ... I love you wife.. HAPPY 31st Mrs Thomas."

Of course, 31-year-old Earl gave plenty of indications he had been working toward this since the arrest.

Shortly before we broke the story in May, Thomas said he and Nina were "back talking." And, just a few days later, Earl shared a diamond pendant he had received from Nina for his birthday.

For her part, Nina shared her own birthday message Friday about personal growth ... writing on social media, "Happy birthday to me."

"A new year of life to grow, be challenged, succeed & fail but get right back up again, to love & be loved, to healing & breaking generational curses, to be vulnerable & also strong, to be wise yet still give myself grace when I make mistakes, to living in my truth and being unapologetically me."