MAN UP DEPT.: Jonas Brothers heartthrob KEVIN JONAS just got his first lesson in Matrimony 101 when bride-to-be DANIELLE DELEASA asked him to decide who’ll be Best Man at their winter wedding – and Kevin blithely informed her he wants BOTH of his famous brothers, JOE and NICK, to stand up for him.

Bridezilla went NUTS, said a source, huffing: “You can’t have two Best Men. You’ve got to choose one!”

Insiders say Danielle groused to pals that having two Best Men is, like, so totally dumb – like, as if she’d ever have two Maids of Honor…Duh, HELLOOO! Danielle then gave Future Hubby his “options” (or, as guys call them, “orders”)!

Kevin could either have one brother serve as a groomsman – or he could designate a good friend as Best Man and put brothers Nick and Joe in the wedding party. (Kid brother FRANKIE, 8, will serve as ring bearer.)

Faced with Danielle’s version of “Sophie’s Choice” – and conflicted by the fact that both Nick and Joe were openly competing for the top spot – Kevin finally stepped up to the plate and made a brave decision.

Firmly putting his foot down, he informed Danielle that she chose who will stand up with her, so he will choose who stands up with him, and that will be…both Nick and Joe. YAY, KEVIN!

Men everywhere will applaud you…and, hopefully, Wifey won’t make you suffer forever!