Jennifer Garner's Hilarious Birthday Message to Reese Witherspoon Involves a Saxophone

Since her split from Ben Affleck, Jennifer Garner seems to be having more fun than she's ever had. From that viral Oscars meme that saw the actress realizing something, to her jaw-dropping red carpet looks, Garner is living her best life right now. And she's not afraid to reveal her nerdy, quirky side, too.

In the most hilarious birthday post to gal pal Reese Witherspoon, who turned 42 this week, Garner writes, "Hey, @reesewitherspoon! I don't know why you're on my mind today.....🎷🎁🎈🎈❤️❤️❤️ #happybirthdayfriend." And you literally won't believe the video she posted for Witherspoon:

That's right. Jennifer Garner plays the saxophone, and she's not afraid to crack out her old band uniform to play Happy Birthday for her besties.

Witherspoon's birthday celebrations were pretty spectacular, and included two birthday cakes, including the most gorgeous, unicorn-themed tower:

She even had a bespoke dress created just for the celebration by her design team at Draper James, and captioned the photo, "Cake for breakfast, anyone? Thank you for all the sweet birthday wishes! Feeling so much love today! I’m one lucky gal":

And she took the opportunity to make a birthday wish with her son, Tennessee:

As for Garner, it was recently reported in Us Weekly, according to a "pal" close to Ben Affleck, that she "put her heart and soul into fixing the relationship and wanted so desperately to turn things around for the children’s sake as well as theirs. She forgave him for so much, and still he couldn’t change."

Basically, Garner is now moving on with her life, and she's using social media to showcase her hilarious side.