Maybe in this kind of situation:
Person: When are you and BF getting engaged?
Me: I'm not sure. But for me, knowing would take the fun out of it.
Person: You should ask him, or at least give him a deadline. You've been together long enough!
Me: Now why didn't *I* think of that?
FWIW, BF and I have been together 7 years. We talk about engagement and our future quite often. But that's our business. We talked about the deadline suggested and both agree it's something that, again, for us, would cause unnecessary pressure, and also ruin the fun of me being sweetly surprised. Again, it's *our* business.
Ugh. I *should* start using all these lines for when the topic comes up... it does almost weekly from various people.... :sigh: I've taken to just answering "I'm not sure, you should ask him".