Singleton Club – Responder – 1♢-2♢

Singleton Club – Responder – 1-2

N
W   E
 
S
K 4
5 3 2
K 10 4
A K 9 6 4

Dealer:

West

W N E S
1 Pass 2 Pass
2 Pass ?

Partner opens 1 and we have a strong hand. They are unlikely to have five hearts when opening 1, so a direct 3NT is perfectly sensible. But we decide to bid 2 anyway, and partner rebids 2. What should we bid?