The Fuller House and Grandfathered star, who has often performed in concert with the iconic band since the mid-1980s, is currently playing the drums on tour with them.
During Monday's concert at the City Bank Coliseum in Lubbock, Texas, several audience members were pulled on stage during "Barbara Ann," when Stamos, 52, brought 29-year-old Jenna McMillan, who has Down syndrome, to the front to dance and sing with him.
"Having Fun Fun Fun on stage with these cuties (and The Beach Boys) Lubbock TX," Stamos tweeted alongside an adorable video he filmed of the moment.
According to EverythingLubbock.com, he also let her take several bows in front of the audience when the song ended.
"I had fun because I watch his show all the time," McMillan told the outlet, while her mom Lisa Ashley said McMillan is a lifelong fan of Stamos' show Full House and has seen every single episode. (Uncle Jesse is her favorite, no surprise there!)
"When he first came out on stage in the middle I took her up there then he saw her and he got down and played the guitar for her," Ashley told EverythingLubbock.com.
Ashley says Stamos' assistant then came over to her and told her he wanted McMillan on stage, and when he pulled her to the front she was "excited and only a little bit nervous."
"It was great," Ashley told the outlet of seeing her daughter on stage. "It was all for her, she enjoyed it and it's something she will always remember so I'm glad about that."