Good reasoning all around. You "know" from trick one that
declarer has the King of
♥, so that suit
can't be right to lead again. So the
Queen of
♥ from partner
can't be a signal to lead more
♥s. It must be suit preference for
♠ and surely partner must be void.
And now I will show you all four hands:
Hey,
partner has the King of
♥ !! What is going on? Is partner a dolt ??
No, you have a good and thoughtful partner. He knew the standard rules about suit preference when third-hand is known to hold a whole boat load of cards in the suit: a high one is suit preference for the higher suit, a low one is suit preference for the lower suit, and a middle one is a come-on (encouragement) in the suit that was led.
He also knew that a lie would be helpful here.
His reasoning: "The King on trick one, yes, that will be understood by opening leader as suit preference .... er , won't it? Wait, often that is
encouragement... here of course it's suit preference, but could opening leader get confused? Hmmmm..... Well, playing the Queen will tell him that declarer has the King, so he won't lead
♥ again, and what else can he think then except suit preference?"
You can see that with any lead other than a
♠ at trick two, declarer has all the remaining tricks.
Be a good partner and don't give your partner unnecessary "quizzes" about how much he knows. Don't test partner needlessly. When you can be clear without cost, be clear. When you can be emphatic without cost, be emphatic. And if you need to lie a little to help set the contract, do it.
NB - partner opened 3
♥ on a 8 bagger when you were red and they were white, applying the rule of 2, 3 and 3/4/5:
1. When we are red and they are white, count your tricks in hand and add two.
2. At equal vule, add three.
3. At favorable, sky's the limit.
He counted 7 + 2 (add
2 at unfav vul) = 9 and opened 3.
Be sure to discuss the rules of preempts with your regular partner. I like the above stated rule, but there are other schools of thought and the main thing is that you and partner have agreement.
NB2 - Of course, you will lead your lowest spade at trick two, as your suit preference for diamonds on partner's return.
Partner opens 3♥.
South bids 6♣, ending the auction.