Yahoo is flirting with the idea of tapping Google to power its search engine.

Google confirmed to Mashable on Thursday that Yahoo is displaying Google search results and ads in addition to those of its current partner, Bing, for a small number of desktop and mobile users as part of a dry run. The company is also running similar tests with other potential search backers.

Google's appearance on the site was first spotted by Aaron Wall on Wednesday in a blog post for search engine optimization firm SEO Book.

The move comes after Yahoo and Bing eased up on a 10-year exclusive deal over desktop search in April, freeing Yahoo to pursue other search engines for the first time in nearly six years. Under the new terms, Yahoo is now only required to carry Bing ads with 51% of its desktop search traffic.

That original 2009 partnership ironically helped set the scene for Microsoft's then-fledgling stab at a search engine to eventually pass up Yahoo in market share.

But the current fraternizing between Yahoo and Google is likely unsettling news for Yahoo's longstanding partner, though a teaser of Bing's financials this week revealed that it's doing a lot better than its painful start would have suggested.

Bing still has high-profile deals locked down with Apple and, as of this week, AOL, which just dumped Google after their contract ended. But Bing hit a bump in the road last year when Facebook cut the search engine out of its platform.

Google previously proposed an alliance with Yahoo back in 2008, but the deal was shot down by government anti-trust regulators, who worried the pairing would quash competition in the industry.

Any big partnership between Google and Yahoo can also be expected to catch the wary eye of the Federal Trade Commission. The search giant dominates around 65% of the U.S. search market share for desktop, while Bing and Yahoo trail with 20% and 13% respectively.

Google is already facing a potentially costly anti-trust case in Europe, where it controls about 90% of all searches.

That said, a potential team-up between the two Internet giants can't be counted out. Yahoo doesn't command nearly the portion of the search market it did in 2008, and the industry has changed in shape since then.

Yahoo did not immediately respond to a request for comment on Thursday.