EXCLUSIVE: Mr. Feeny Is Officiating Shawn Hunter's Wedding on 'Girl Meets World' and We're Freaking Out From F

Mr. Feeny! Mr. Fee-hee-hee-heeeeee-nay!

William Daniels, who has played the ultimate advice-giver since 1993, is back and he's just in time for a Girl Meets World wedding.

Shawn Hunter and Katy Hart are tying the knot in a spontaneous and oh-so romantic rooftop wedding -- and only ET has your exclusive sneak peek of the guest of honor's grand debut!

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Mr. Feeny -- aka the man with more job titles than anyone else on TV -- is officially officiating Shawn's wedding and we're freaking out from all the nostalgia feels.

"Just go with it," the 89-year-old actor quips when Riley questions his new role in our first look scene above. "I am many things to many people."

And to us, he will always be our favorite TV teacher of all time. (Sorry, Cory.)

Shawn's Girl Meets World wedding airs Friday, August 12 at 8:30 p.m. ET/PT on Disney Channel.