Controversial topic - infertility issues

Hi Ladies! My husband has been diagnosed with very low T levels which have resulted in having no sperm. We are going through genetic testing next week and seeing if we can find sperm by extracting and then doing <a href="https://glowing.com/glow-fertility-program">IVF</a>. However, there is a chance we may not find any. We discussed using a donor so there was some genetic relation. THEN My mother in law proposed something way outside my comfort zone - using my brother in laws sperm as a donation (which he volunteered). She even said her husband (my father in law) would donate. All three guys are alike both personally and look alike. But this is weird to me - and of course worst case scenario. But she said it may make us feel better knowing where the donation came from. Has anyone heard of such a thing? Not sure if I can get past how weird it is.