u/Existing_Life_7303

My brother in law (24 m) is goinf out with a 17 year old girl who is still in school. I found this out over the weekend and after my mother in law saying they’re going out I just made a remark that it’s a strange age gap to which my mil said no it’s not so I said I won’t be letting him take my daughter (9f) out on days out anymore like he would usually have the odd time. She lost it at me and says I’m been so unfair and we’ll have to cut communication because of it. AITAH??