Ulrich believes that affairs can't harm a truly good marriage. That's why he's set his sights on the attractive Jutta. Jutta believes that his life so far can't be all there is to it. That's why she's set her sights on Ulrich. Sigi believes that his marriage to Jutta could be in jeopardy because of this. Therese believes Ulrich is intelligent enough not to completely succumb to his sexual urges. But she's wrong.