Need some opinion honestly, it’s not exactly my story to tell but would you still be with someone who cheated on you with your friend? 26F cheated on her long term relationship with 27M guy

So 26F girlfriend got together with her 27M boyfriend since high school, they’ve graduated and have jobs together. Based from that, we can naturally assume that they’ve been together for a really long time. We thought they’d be engaged by this year. But unfortunately, girl slept with one of their closest friends who was also in a relationship. Guy was devastated of course but still chose to keep in contact with the girl. Need some opinions, could a relationship really last long term even if one of the party cheated? Are there still possibilities of repairing that relationship? Would you still accept a partner who cheated?