The issue is not about trusting her husband, I don’t think anyone is saying he’s cheating on her..it’s just inconsiderate of his wife’s feelings..the partner who has the complaints is the one who should be heard and both should come to a middle ground that satisfies both partners, the husband is not the one complaining so the focus is on the wife’s feelings because she is the one that is being hurt…he doesn’t have to be touchy feely with a female cousin who had romantic feelings for him even if he himself rejected her..his wife is not comfortable with it, not because she doesn’t trust her husband is because other people can often get involved to ruin relationships..seems like shes being wary of her more than her hsuband..it’s not all that rare to hear about relationships being sabotaged by others including relatives..better to avoid such situations..regardless of her reasons or how absurd it may sound, he should care about his wife’s feelings over a cousin..as you know marriage is a give and take, she’s not telling him to cut them out of his lives or not enjoy..she’s not being unreasonable by saying just avoid being touchy feely with another female regardless of his relationship with her, he can still enjoy his cousins company in many other appropriate ways