This is the thread in question: https://www.reddit.com/r/TwoXChromosomes/comments/ax0svt/how_do_you_politely_stop_seeing_a_guy_because_of/

TL;DR woman rejects man for having a significantly below averaged sized penis (4 to 4.5 inches). She asked him for his size beforehand and he said it was nothing out of the ordinary.

What's the range that most women would be OK with? Average to above average but not huge? It seems like a unanimous conclusion in the comment section that below average is a dealbreaker.