Hi xxx, It was very nice talking with you regarding the project x. I am glad that MR.A will start to work on it. I am willing to assist him at any time. If I am asked which project I am working on,I will let the person know that I am mainly working on Project C. Thank you very much for all the help you've given me.
Cheers,
Hope this helps. If I were you, I would rather lose my job than lie.