Simon Cowell buys ring to propose to Lauren Silverman

Simon Cowell has bought a ring to propose to pregnant gal-pal Lauren Silverman.

Sources revealed that the 54-year-old music mogul is "mad about her" but may wait until after she gives birth to their baby boy, Us Magazine reported.

The X Factor mentor had previously hinted that he would one day marry the 36-year-old New York socialite.