This is HUGE, if true!! TMZ reported on Thursday that Britney Spears' son Sean Preston Federline made a big change to his Instagram. They say the 20-year-old son of the Princess of Pop and Kevin Federline updated his IG handle to only feature his momma's name! We can't verify this claim because his account is private, but the outlet said he formerly went by "Sean Preston" on the app, and now is using "Sean P. Spears".