New Revised Standard Version
But he answered them, “An evil and adulterous generation asks for a sign, but no sign will be given to it except the sign of the prophet Jonah.

Contemporary English Version
But Jesus replied: You want a sign because you are evil and won't believe! But the only sign you will get is the sign of the prophet Jonah.

New American Bible
He said to them in reply, “An evil and unfaithful generation seeks a sign, but no sign will be given it except the sign of Jonah the prophet.

Douay-Rheims Bible
Who answering said to them: An evil and adulterous generation seeketh a sign: and a sign shall not be given it, but the sign of Jonas the prophet.

Who answering said to them: An evil and adulterous generation seeketh a sign: and a sign shall not be given it, but the sign of Jonas the prophet.

adulterous.

Isaiah 57:3 But draw near hither, you sons of the sorceress, the seed of the adulterer, and of the harlot.

Mark 8:38 For he that shall be ashamed of me and of my words, in this adulterous and sinful generation: the Son of man also will be ashamed of him, when he shall come in the glory of his Father with the holy angels.

James 4:4 Adulterers, know you not that the friendship of this world is the enemy of God? Whosoever therefore will be a friend of this world becometh an enemy of God.

no sign.

Matthew 16:4 A wicked and adulterous generation seeketh after a sign: and a sign shall not be given it, but the sign of Jonas the prophet. And he left them, and went away.

Luke 11:29,30 And the multitudes running together, he began to say: This generation is a wicked generation. It asketh a sign: and a sign shall not be given it, but the sign of Jonas the prophet. . . .