My cheating ex married the OW but the marriage failed within two years. Ended up happy with someone else further down the line.
A serial cheat I know lost his wife and family because of his affairs. Didn't end up with the OW (there were too many) but was so devastated over losing his family he completely changed and stopped his cheating ways for good.
Another serial cheat, my former boss, got found out by his first DW and lost everything. Got remarried but carried on cheating, was just better at hiding it. Had a long term affair (7 years) with my friend. Stayed with his DW. Still together and happy. Or he is, at least.
Another, not a serial cheat, fell in love with an OW at work. Left his DW for her. Felt so guilty he had a breakdown. But stayed with the OW, married her and they had a DC. Still together 20 years later and very happy.
Another, of the serial cheat variety, still with DW of 30 odd years. Has cheated all his married life. DW - a lovely woman - won't divorce him because she loves him too much. Kicked him out on several occasions, when he would then dump the OW and beg DW to give him another chance. She took him back each time. Still together. And happy, at least on FBook.
Finally, both the Dimbleby brothers left their long-term marriages for younger women.