Jimmy Kimmel is putting Khloe Kardashian on BLAST -- asking the question we all wish we could ask her: "Why do you keep dating professional basketball players?!"

The Live! host grilled Khloe: "I do want to ask about this character you had a baby with. Is it time to stop dating basketball players?" Ms. Kardashian finally conceded, "I don’t know, you know, I like what I like, what can I say? ... I do agree, I should listen to my M.J., my grandmother and should probably start to date, like, accountants or something like that."

Meanwhile, Kimmel get a REVELATION out of Kim, regarding baby #4's name -- we can't believe who she might name the little boy after ... Rob! She said, "I was truthfully thinking about just naming him Rob, [after] my brother. But then it’s like, North, Saint, Chicago, Rob. It doesn’t really go. I really was feeling like that, or Robert. And my brother approved it, so that’s, like, our one kind of name. I like Rob West."

Wow! That'd be crazy if Kim and Kanye have a little Rob running around!