Dear Miss Snark:
I am looking for a new literary agent, after spending a few (unfruitful - ie she didn't sell anything) years with a very respected agent who has been around for dogs years and has a very full client list (I felt I wasn't on her radar, really).
I am in the process of querying several people. One young person at a very large, well-known literary and talent agency asked me point blank if I were approaching several people - I parried, and referred to the agent I just jettisoned. My feeling is it's simply not necessary for her to know what I am doing or am not doing, since she has not offered to represent me - she's still working on reading a proposal and a few very short book chapters for a nonfiction project.
Was I (or am I) under any obligation to inform her I'm shopping?
Most of us know where we rank in the pantheon. I'd be a self obsessed idiot (rather than just self obsessed) if I thought you were shopping for a new agent and only talking to one person. Now, were I Binky Urban, Nicole Aragi or Jenny Bent..well, that's a horse in a different neighborhood.
Mostly we ask cause we want to know what the competition is and who else has her claws into you.
You can finess it by saying "I'm investing a great deal of thought and energy into finding a good match".
Don't lie ("you're my one and only") and don't name the competition ("you're number six ..but with a bullet!").
It sounds like you're doing exactly the right thing.