3♣ seems obvious, absent agreements a la Roland's Garozzo treatment. e.g. xxxx AKxx Axx Kx will make game easily. How can partner evaluate ♣Kx if we just bid 3♥? 3♦ is guaranteed to end a brief partnership, imo, unless it asks for really good ♦. Logically it should ask for good ♦, since we already know partner has better ♦ than ♣. fwiw what is 2N here?