'Adulterous' in the Bible

But he answered and said unto them, An evil and adulterous generation seeketh after a sign; and there shall no sign be given it but the sign of Jonah the prophet:

An evil and adulterous generation seeketh after a sign; and there shall no sign be given unto it, but the sign of Jonah. And he left them, and departed.

For whosoever shall be ashamed of me and of my words in this adulterous and sinful generation, the Son of man also shall be ashamed of him, when he cometh in the glory of his Father with the holy angels.