Justin Timberlake, Lance Bass feud? Former NYSYNC buddy 'won't sing' at Michael Turchin wedding ceremony?

Former NSYNC crooner Lance Bass is allegedly "enraged" that Justin Timberlake won't commit to singing at his wedding.

Pause for dramatic effect.

So here's the story according to the National Enquirer.

Bass is totally "pissed off" that JT still hasn't said "yes" to performing at his marriage ceremony when he weds actor Michael Turchin. The popular gossip tabloid reveals, “Lance told his pal he’d pick a wedding date based on JT’s availability to sing at the reception, and expected an instant yes - but Justin started hemming and hawing about not being sure of his upcoming schedule.”

An alleged source goes on to explain, "Superstar Justin doesn't want to be anybody's wedding singer, and tried to let his pal down easy... But Lance is getting the message - Justin's not really a pal at all."

Sounds a bit extreme...

According to Gossip Cop, a rep for Bass insists that this report is "completely untrue." Bass and Timberlake aren't "feuding" over the "Mirrors" singer's ridiculous "indecisiveness." 

FYI - Bass proposed to Turchin in New Orleans back in August. The two have yet to reveal any wedding plans.