I was having lunch w/ some coworkers today and the conversation went like this: Coworker#1 brings up her sons recent engagement. Coworker#2 adds, "Well, you know, it has been 5 months..." Coworker#1 say something like, "Oh yeah, you're right" and they both nod knowingly. I asked Coworker#2 what he meant and he says, "They've been living together for 5 months, so its kinda the rule to get engaged then..." I said that I had never heard of this and that I've been living with the bf for ~9 months. He then proceeds to list like, 5 or 6 couples he knows that have "followed this rule" and kinda gives me the "poor you" look. Fortunately Coworker#3 (a very well respected staff member) chimes in with, "What about me and my bf? We've been living together 32 years..." That kinda put a stop to that part of the conversation, but I'm still a little confused. I thought I was well versed on relationship stereotypes/myths, but this one is new to me. I think its bullshit, but I was wondering if anyone else heard this or any variation there of?