I (28f) am having my third (and final) child with my husband and I have a scheduled c-section and hysterectomy planned. My periods started when I was young (9) and I have suffered with them ever since. They're extremely painful, heavy and (very) long. I wasn't even sure if I could get pregnant with my issues but I knew I wanted children so I delayed even when the option was originally presented to me. It was worth it but these extra years have been torture on my body.

My sister (31f) is struggling with infertility. She's had some fertility treatments but nothing has worked for her yet. It was suggested to her on more than one occasion that she could consider a surrogate. She was very against it for so long. In another situation, one where I didn't have all the problems I have, I would have offered for her because we're so close. But I need to be done. I don't know if I'll honestly survive like I have been if I wait another couple of years or more so my sister can have kids.

In December my sister came right out and asked me not to have the hysterectomy yet and to be her surrogate so she can be a mother too. I told her I was so sorry and if my body wasn't giving me the hell it is, I'd do it for her, but I couldn't delay it any longer. She got upset but told me it was fine and she understood. She'd get over it. I could tell it bothered her but I didn't want to fight about it.

Then Christmas came and my BIL got involved. Our whole family was together Christmas Day and when everyone was busy he asked to speak to me and then he berated me for my selfishness and he said if I loved my sister as much as I said I'd delay it like I did for my own selfish reasons. My husband and my mom heard him and they stepped in to defend me and my husband told my BIL to back off and nobody should ever be put under pressure to carry a pregnancy. Mom said emotions might be high around it but none of this is my fault and he shouldn't attack me like that. BIL told them I broke my sister's heart and he was pissed at me for it. My mom told him again that it wasn't my fault.

The rest of Christmas Day was strained and afterward my sister told me she was sorry about her husband but they were just so upset and they felt robbed of having a baby biologically related to the two of them. I told her I was so sorry and I was here if she needed me. BIL reached out and said my sister might be sorry but he still thinks I'm incredibly selfish.

AITA?