The actor added that the entire cast kept the newly engaged couple's romantic relationship a secret for "a couple years" JC Olivera/Variety via Getty; Steve Granitz/FilmMagic Gianni DeCenzo is ...

but their co-star Gianni DeCenzo was far from surprised. Tanner and Mary went public with their romance at the Cobra Kai series finale premiere event, where they showed up wearing matching rings ...

Gianni DeCenzo is ready to be in Tanner Buchanan and Mary Mouser's wedding party! "I want to be the ring bearer," DeCenzo, 23, joked in the episode shared via YouTube on Thursday, Feb. 20.