I let my mother-in-law move in with us.
There's a trope that an angel might be given a big halo in heaven after they die if they did a particularly selfless act in their life. Here, the above-and-beyond act was letting a mother-in-law live with him and his partner. In general, having a partner's parents move in is very hard, because the in-law may interfere with the couple's independent, day-to-day romantic relationship, and so agreeing to this is a huge sacrifice. It's funny in part because this isn't the biggest possible sacrifice in life, but is under-rated as a selfless act.