The E! reality star flaunted her post-baby bod in a skimpy bikini while hitting the surf with sister Kim in Miami Beach, Fla. on Saturday.
Kourtney, 31, welcomed her son Mason -- her first child -- last December. (Mason's dad is her boyfriend Scott Disick).
Even Kourtney's little sister is envious of her slimdown. "My sister weighs less than I do, so that's kind of fascinating to me!" Kim, 29, told Us Magazine. "She looks amazing."
How did Kourtney do it, then? "Definitely breastfeeding helps," she told Us. "Everyone says that, but it's really true -- and it's just being a busy mom."
She added that motherhood makes her feel more -- not less -- sexy. "It brings out a whole new glow or something," she told Us.
Credit: Us Magazine
