Hi Rahul,
Have you checked your Theme? I use a ProPhoto theme and it has a setting for SEO, whereas I use Yoast as well. I Googled Multiple Meta Description and found your post when I decided to double check the actual theme. I’m hoping turning off the SEO setting in my theme settles the problem of multiple meta descriptions in Bing Webmaster Tools.
I’ll keep you posted. 🙂
