Bottoms Up, Kim!

6/6/2007 1:24 PM PDT BY TMZ STAFF
Jennifer Lopez and Jessica Biel had better watch their, er, backs -- cuz there's a new booty-ful babe on the block -- Kim KardASShian!

Kim was showing off her colossal badonkadonk again on Tushday night outside Koi -- where she was anything butt coy!

Thanks, Kim, for pulling up the rear!

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