Well hell yes I will! Especially since both X and Y are on my short list of agents I would like to work with. What an awesome opportunity!
The thing is, both X and Y are at the same agency. Now some agencies specifically say "do not query multiple agents" but this isn't one of them. HOWEVER, I was still nervous of querying them both simultaneously. Some asshats out there will use in their query "so and so said I should email you" when so and so absolutely did not do that. They assume agents are enemies and don't talk to each other. Publishing is small folks and agents absolutely talk to each other. If you lie, you will get caught.
So I didn't want to appear to be one of those people by querying two agents at the same agency that I was contacting them on a recommendation even though it's absolutely true. I weighed the merits of both and chose which to send to first. And now I'm waiting. It's hard to wait for a response to queries. Harder still when you have a recommendation that you're hoping will help your already awesome manuscript (of course) rise to the top of the slush pile. Harder to the umpeenth degree when some agencies (a la Nelson Literary Agency) frequently send responses in two weeks or less. I've had agents respond to queries six months after I originally sent them. One time, I finished a manuscript and then received a rejection for the manuscript I had written BEFORE that one. There is not a set schedule for this kind of stuff.
So here I am waiting and it dawns on me. Shit, NaNoWriMo is here! With NaNoWriMo comes the SUPER-SLUSH! That period at the end of November through the middle of January where hopeful participants think their 50,000-word quantity-over-quality block of text is the next Harry Potter. I've made the mistake of querying during the super-slush. If you are serious about your career, just skip this time period. It's a billion times harder to get noticed. There are holidays and there is a ton of shit coming in.
So I am going to query second agent now so I don't get lumped in with the pending onslaught of 50k novels. If you're working on your query right now, I recommend you get that thing polished and out the door.