Is it permissible to have intercourse with the first wife after secretly marrying another, knowing that she stipulated that no one else be married alongside her?

Scholars have differed regarding the ruling on a woman stipulating in the marriage contract that her husband not marry another wife. The more preponderant opinion is that this is a valid and binding condition. If he marries another wife without her knowledge, he should not have intercourse with her before informing her, and she has the choice, after she learns, to either remain with him or separate.