Could he marry again?
Question:
If a Christian man marries a woman who divorced her husband, without it being for adultery, he lived with her for several years, then she cheated on him, so he separated from her. Is he still an adulterer? Could he remarry a free and Christian woman?
Answer:
"But I say to you that everyone who divorces his wife, except for the reason of unchastity, makes her commit adultery; and whoever marries a divorced woman commits adultery" (Matthew 5:32).
While you were married to this woman, you were living in adultery. The solution is to divorce the woman you had no right to be married to. Assuming you have not been married before, you can marry someone with the right to be married.