Haworthiia, you is a wise-wise lady!
CoraPirbright - I think you got it spot-on!
My dm did that. Well, she didnt show me the ring but she did tell me that he was going to ask me. I was flabbergasted and annoyed with her and when I asked her why she did it, she said she "wanted to give me the joy of it". When I said it wasn't hers to give, she didn't really have an answer but she does have a bad history of trying to be really over-involved in my life so it didn't really surprise me. I didn't tell dh as he would probably have called it off in a fit of peak and also I didn't want their relationship to get any worse than it already was (he finds her really annoying). So I had to feign surprise and the question-popping moment was a bit crap generally so I am really sad I don't have a nice story to tell when everyone shares theirs. I know its really shallow and its the marriage that matters, not the proposal yadda yadda yadda and I am surprised by how sad it makes me but I guess I can't really help it.
This thread is split between those who think OP should tell OH ASAP and those who think she should tell him after the proposal. I'm with the ASAPs, because D-future-MIL has already trashed it for the OP. She has to be a fuckinggood actor if she can fake her surprise after this, and then she turns it all to ashes by telling him she already knew.
That makes it a RUBBISH engagement story for BOTH of them. OP can make a NEW story (for both of them) if she declares as early as possible that she knows.
And there's two ways to get engaged, and both of them are playing out on this thread....
One is one of the couple saying ".... so, let's get married!" (or an equivalent) and then they go off and choose a ring together before announcing to the world.
The other scenario is that one of the two arranges a 'surprise' which involves a ring.
Both are equally valid and lovely It's not surprising that in scenario two the one proposing seeks opinions, practices, etc.
I imagine that the OH of OP left his ring at his DM's house, and she took photos and shared them. Totally out of order of her!
I feel quite invested in this thread!