AIBU to be annoyed (light hearted)

[Kerantli]

DP and I went to my DMs wedding on Friday and I heard the tail end of a conversation between DP and DM (walked through a door just as DM mentioned something about having permission)

Now, no matter how often I ask DP what they were talking about he says "it doesn't matter". I keep telling him that "if it doesn't matter, you'd tell me" which is true, he would.

Since then we've just gone round in circles of me asking what he asked DM with the same answer we both end up laughing when I ask

So, WIBU/AIBU to be ever so slightly annoyed he's keeping something from me?

It must be something good. I bet he's going to propose!

Maybe they are planning a surprise for you?

That's the only thing I can think of, but don't want to get my hopes up just in case it isn't that

I'm not very good with surprises, and when I asked my DM about it she claims she's "forgotten" (to be fair, she was on prosecco from about 2pm, then pimms, then wine), so it is entirely possible she really did forget what DP asked

I find it immensely irritating when someone walks in on a conversation and asks what the conversation is about - don't be so bloody nosey!
'We were talking about you, not to you' would be my response

I guess I'm not actually used to not knowing what is going on in DPs head after 5 years together

I've dropped it for the moment though, probably not for very long as last night I did get "it's not the right time" from him