Divorce is serious, yet it is justified in cases, while it should not be thought for a first option in any cases. If a spouse is stealing, lying, turning against the other spouse, that must be basis. Serious continued deception would justify it, from the other spouse. Remember still that Leah, and Jacob, were both in a time before the law from God given to Moses, who descended from them. Leah was not the one herself who was deceiving Jacob, and what had Leah ever done wrong? We are all sinners, Leah too, but that we are sinners is not itself any justifying basis for divorce. None of us know if divorce was already an option at that time when Jacob and Leah were married, while there was no stated rule for a man having only one wife.
Mat 5:31 It hath been said, Whosoever shall put away his wife, let him give her a writing of divorcement:
Mat 5:32 But I say unto you, That whosoever shall put away his wife, saving for the cause of fornication, causeth her to commit adultery: and whosoever shall marry her that is divorced committeth adultery.