The wife went away for 3 days with the child, leaving the husband at home (he had to work). She came home and was changing the sheets on the bed and she found a used condom in the bed. The husband's reaction was "How did that get in there?" and she naturally lept to the conclusion that he was cheating, but he swears black and blue that he isn't. The only other explanation is that their flatmate was doing it in their bed with one of his gay lovers. The flatmate has not been seen or heard from since the condom was found, and the husband is still denying he is cheating.
So what would you think had happened? And how would you react?