I disagree with this tell him/her, he/she has a right to know bandwagon. What will happen if you keep quiet? Nothing. Is her BIL going to shit on himself? It’s not likely he’s going to rush to spill the beans as many Redditors here suggest. What happens is she tells? Family drama, sibling estrangement, marital problems and permanent changes in relationship over a kiss. Just avoid being alone with him in future. If he comes to your house when your husband is out tell him you’re just going out. I have a feeling he won’t dare to repeat it again.
I am a believer in shedding light on evil. So I would encourage you to get her to talk about it and support her.
I disagree with this tell him/her, he/she has a right to know bandwagon. What will happen if you keep quiet? Nothing. Is her BIL going to shit on himself? It’s not likely he’s going to rush to spill the beans as many Redditors here suggest. What happens is she tells? Family drama, sibling estrangement, marital problems and permanent changes in relationship over a kiss. Just avoid being alone with him in future. If he comes to your house when your husband is out tell him you’re just going out. I have a feeling he won’t dare to repeat it again.
Simply don't add any ages next time rather than lying.