Great news, and best of luck with it. Just goes to show that honesty can be the best policy (and can even push things along a little.)
I think the difficulty is that 'others interested' can mean so many things, from Agent A having just asked to see the full MS when Agent B asks the same, to a meeting with Agent A for coffee tomorrow to offer representation. It's the latter that Agent B really, really wants to know about before s/he devotes most of her Saturday to reading and thinking about your MS and how she might sell it... which is understandable, though it does sometimes make it so difficult for writers.
I also think honesty's the best policy because you never know when the dishonesty might come back to haunt you. It's a very, very small industry.
Emma