Russell Simmons: My Ex Is the Best at Sex Ed!

Russell Simmons would give his ex-wife a PhD in Sex education ... after watching her lay into their daughters about the dangers of "popping the coochie."

Russell flew into LAX a few hours after one of his daughters posted video of Kimora Lee Simmons having "the talk." Sure, it was a direct, and maybe even a little crude.

But Russell told us he LOVED his ex-wife's technique, and lauded her with even more compliments.

Just a guess, but he's probably just glad Mom had the "wrap it up" convo instead of him.