Sisters Kim Kardashian and Kylie Jenner spent the day by the pool on Sunday -- and made sure to share some personal pics for all their fans.

Of course, Kim is no stranger to posting bikini photos on her Twitter page ... but it seems to be rubbing off on 14-year-old Kylie.

Kim kicked it off first, posting three different shots of her in a snakeskin two-piece that barely contained her most famous asset.

Kylie then followed suit, posting her own pic of herself in the family's pool in a stringy bikini ... while blurring Kim out of the shot!

Check out more of Kim's hottest TwitPics in the gallery above. She's got a lot of them.

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