Hide meta name=”keywords" from Bing, Show Yahoo?

I recently followed a test of meta name=”keywords” and results were that Google ignores them, Bing doesn’t list them but apparently if they find issues with them that they flag you as spam, Yahoo says they ignore them but they don’t. Ask uses them. Many other smaller and overseas search engines use them.

So I’m wondering if there is a conditional way I can hide the whole tag from Google and Bing, but show everyone else.