Even by his own admission, Lance Bass is planning an extravagant wedding ... but the former boy-bander might have a bigger day in store than even he himself realizes.

Lance and fiance Michael Turchin, who recently got engaged after nearly two years of dating, might be upstaged at their own nuptials -- by another 'N Sync reunion!

Lance and his bandmates famously reunited at the 2013 MTV Video Music Awards, for their first onstage appearance together in more than a decade. It was a performance that was much too brief for many fans, so hopes remain high that more is in store.

And Lance, who is planning an "over-the-top, like you're going to a Met Ball type of situation" for his and Michael's Big Day, is doing his part to fan the flames of those hopes. Saying that the other 'N Sync-ers "better be" at the reception, he adds that there will be a stage available for any off-the-cuff, champagne-fueled performances.

So we guess there's no bad blood over the whole band not being invited to Justin Timberlake's wedding?