The singer has rehearsed a "tongue-in-cheek" routine to his former boyband's song 'It's Gonna Be Me' along with his ushers and best man, The Sun reports.
© PA Images / Charles Sykes/AP
"Justin has been working on this for months," an insider claimed. "Jessica used to love the track growing up and he wants it as a special treat.
"It will be very much tongue-in-cheek. There will be loads of exaggerated boyband moves and poses. She's going to love it."
The video for 'It's Gonna Be Me' memorably saw Timberlake and *NSYNC bandmates Lance Bass, JC Chasez, Joey Fatone and Chris Kirkpatrick made up as string puppets.
Timberlake and Biel are said to be tying the knot in a low-key ceremony in Italy.
The couple reportedly became engaged in late 2011 after an on-off relationship of five years, but Biel only confirmed reports this summer.
Digital Spy breakfast show - watch Catriona Wightman discuss the day's biggest stories including Adele, Emmerdale and Kylie Minogue:
