3♥ is supposedly weak but they learned WJS's last week and may not know exactly what they are doing.
Matchpoints against one of the weaker pairs.
Partner leads the ♠5, K, A and declarer plays the T.
In order to get partner's opinion, you play the ♣A and partner plays the J (UDCA).
How do you continue?
For extra points, how would you continue holding ♣A2?