Heidi Montag hires private investigator to catch cheating boyfriend

41373, SANTA MONICA, CALIFORNIA - Tuesday June 8, 2010. E-TABLET/IPAD & MOBILE PHONE APP PUBLISHING REQUIRES ADDITIONAL FEES**

Heidi Montag has reportedly hired a private investigator because she’s convinced boyfriend Spencer Pratt has been cheating on her.

The reality starlet has already filed for legal separation from her blonde, beardy husband, but now friends are saying she’s become convinced he cheated on her a few months ago. The PI she’s hired will apparently be checking Spencer’s spending to see if he’s splashed out on gifts for another woman.

While this is going on, Spencer claims that he also thinks Heidi is cheating on him with one of her bodyguards.

And if Spencer thinks he’s not getting enough media exposure, at the moment he’s busy recording a rap album. On dear…