A clash on the Enterprise deck?? George Takei sets his phaser to stun as he talks exclusively to ET's Thea Andrews about William Shatner's now-infamous YouTube rant against him -- and what's more, Takei disputes the claim that he didn't invite Shatner to his wedding!

Shatner asserts in his Youtube video that Takei holds a grudge against him and has a "psychosis." Takei, a recurring guest announcer on "The Howard Stern Show," has been known to tell unflattering stories about Shatner on the air.

"Star Trek"'s Mr. Sulu also tells Thea that he, like fellow celebs Brad Pitt and Ellen DeGeneres, opposes California's Proposition 8, which would ban same-sex marriages in the state. Last month, Takei married his partner of 21 years, Brad Altman. Prop 8 would also invalidate their union.