The re-percussions of dating a drummer.

Travis Barker gifted girlfriend Kourtney Kardashian’s daughter, Penelope Disick, a set of drums for her 9th birthday Thursday.

Kardashian, 42, posted a photo to Instagram of Penelope, whom she shares with ex-boyfriend Scott Disick, playing the pink drums, which were personalized with her name.

“My birthday girl! My favorite girl in the entire world I am so happy and proud to be your mommy,” Kardashian captioned the post. “I can not believe that you are 9 🥺🥺🥰🎈My life is sooooo much better because of you.”

She also shared a video of Penelope playing her new instrument as the Blink-182 drummer, 45, assisted and offered tips.

“Penelope you’re a rock star 🥁 HAPPY BIRTHDAY 🎉,” Barker wrote in the comments section of Kardashian’s post.

The Poosh founder began dating Barker in January, and they have been getting more and more serious ever since.

The couple have shown plenty of PDA on Instagram and in public, and Barker even called Kardashian the “love of my life” in May.

The “Keeping Up With the Kardashians” alum shares Penelope and sons Mason, 11, and Reign, 6, with Disick, who is currently dating much-younger model Amelia Gray Hamlin.

Disick, 38, recently gave Kardashian and Barker’s relationship his blessing, saying during the “KUWTK” reunion, “I think if you really love somebody right, you want them to be happy no matter what. So, I do give her a blessing to be happy.”

Barker, for his part, shares son Landon, 17, and daughter Alabama, 15, with ex-wife Shanna Moakler.

Moakler, 46, made headlines earlier this year when she claimed that Barker had an affair with Kourtney’s sister Kim Kardashian during their marriage, though Kim, 40, denied that they were ever involved.