Britney Spears' one-time love rival, Shar Jackson, has gone under the knife and spent $15,000 (GBP7,700) on a tummy tuck and breast lift. Kevin Federline's ex-girlfriend is looking forward to wearing a bikini again this summer (07) after spending years covering up the stretch marks she was left with after giving birth to four kids. The actress says, "For a long time, my figure was like my badge of honour... I tried everything, but nothing got rid of the stretch marks." She tells America's In Touch Weekly magazine she underwent the secret surgery in Hollywood in late January (07). She adds, "I feel sexy and amazing. I'm looking forward to wearing two-piece swimsuits this year. The last time I wore a bikini was when I was 16."