By Kate Ward
Updated March 29, 2011 at 06:15 PM EDT

Britney Spears’ ex-husband, Kevin Federline, is expecting his fifth child with his professional volleyball player girlfriend Victoria Prince, a source tells People. The reality star and one-time rapper, known for his “Popozao” track, has four children: Two with Spears — Jayden, 4, and Preston, 5 — and two with ex-girlfriend Shar Jackson (Kaleb, 6, and Kori, 8). Federline, 33, and Prince, 28, have been dating two years; this will be Prince’s first child.