Jesus did not condone adultery but he was radically different in his view of it. ‘Where are your accusers? Neither do I condemn you, Go now and leave your life of sin’. John 8:1-11. This incident only features in the Gospel of John, which I have little regard for, due to the drastically differing nature it portrays of Jesus. Additionally, many of the earliest manuscripts do not contain the quoted verses above.
However, it is consistent with the synoptics, in that Jesus dispenses with the idea of following the letter of the Mosaic law, he absolves without recourse to Priestly absolution, it errs on the side of being merciful rather than sacrificial. It reflects the wisdom of Jesus, advocating forgiveness, offering a chance of redemption.
Perhaps one of the most challenging aspects of Jesus’s teachings with regard to adultery was his reference in the Sermon on the Mount, Matt 5:27.28, “You have heard that it was said. You shall not commit adultery. But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart“. Now if Jesus can forgive physical adultery, he can certainly forgive lustful thoughts, he doesn’t condone such musings, but in seeking the wisdom of Jesus his rationale resonates with me, If I would be a follower of ‘The Way’,’ self control, mind over matter, self mastery is something worth achieving.
LDS implications with regard to adultery and plural marriage, if you take the view that Jesus only sanctions one wife per husband, then plural marriages are adulterous!