The story of Claire Randall, a married combat nurse from 1945 who is mysteriously swept back in time to 1743, where she is immediately thrown into an unknown world where her life is threatened. When she is forced to marry Jamie, a chivalrous and romantic young Scottish warrior, a passionate affair is ignited that tears Claire's heart between two vastly different men in two irreconcilable lives.
Claire Randall is a married combat nurse from 1945 who is mysteriously swept back in time to 1743 where a war is also going on. She is forced to marry Jaime, a romantic young Scottish warrior, in that period, because someone (who looks like her husband from 1945 and is played by the same actor) wants her persecuted and marriage is her way out of that. She and Jaime fuck just before their wedding in Season 1, Episode 7 at 13:27 and have their honeymoon at 41:14 and 51:00. Their honeymoon sex scenes are hot because Claire has gotten to know and like her new husband more and so she is into their lovemaking more.
I haven't seen the entire series yet. If you know more hot cheating scenes in the later episodes, please put it in the comments below.