AceShowbiz -

Kim Kardashian and her older sister Kourtney Kardashian raised the temperature on "Piers Morgan Tonight" when they decided to discuss about sensitive issues like breasts and sex tape. The voluptuous women revealed that one of them went under the knife and that Kim's sex tape was indeed an embarrassment.

"There's a lot of plastic surgery rumors that swirl and I'm the first one to be super honest," Kim said when talking about her large boobs. "They are real. They are completely 100 percent real." It's not the case with Kourtney. She confessed, "I used to make fun of [Kim] when we were little, and then I went and got surgery."

The body issue became the main topic of the night. "We're not your typical stick-thin skinny girls you see in the magazines," Kim said, adding "When I am heavier I see it goes to my thighs so when that happens I will go to the gym and it makes me feel a little bit more secure and confident."

The sisters went and stood next to cardboard cut-outs of themselves and Piers Morgan asked them to say what they were not happy with about their bodies. While Kourtney thought that her boobs looked uneven on that cardboard, Kim said, "I must say I am pretty content. I am pretty confident."

Moving to a different subject, Piers asked Kim about the infamous tape of her and ex-boyfriend Ray J. "There's embarrassment and shame and so much that comes along with it," Kim admitted. "I think that I was so lucky to find a boyfriend at that time in [Reggie Bush]. [It] was something he really helped me through, and he picked me up when I couldn't pick myself up."