The former Disney star also got playful while posing with the bridal party on Instagram.
Selena Gomez takes her maid of honor duties very seriously!
The 25-year-old singer (and her back-to-brunette tresses) headed to her home state of Texas this week for her cousin Priscilla DeLeon's bridal shower -- where it's clear she was the life of the party.
Gomez appeared to join the bridal party for a dress fitting, where she surprised DeLeon with her dream wedding gown.
"When your maid of honor makes your dream dress a reality and surprises you with it!" DeLeon captioned a sweet video of herself and Gomez posing with a sign reading, "I said yes to the dress."
The former Disney star also posed with the group for a Boomerang, in which DeLeon and her bridesmaids all rose a glass to cheers the occasion -- while Gomez knocked back the bottle!
The group later headed to Manny's Uptown Tex Mex restaurant for dinner and drinks, where amid celebrating, Gomez stopped to take photos with fans.
As for whether Gomez will be heading down the aisle herself anytime soon, a source told ET that she and Justin Bieber are taking their newly-rekindled relationship very seriously, and are even receiving private couples spiritual counseling to stay on track.
"They are very serious," the source said of their current relationship. "They are in this for the long haul. They may be young, but don’t forget, both their parents married young and had children young, so this is normal to them, plus they’ve already accomplished so much career-wise. They’re at a point in their lives where marriage and kids are definitely on the table."
See more in the video below.