Bob's birthday is on Monday. Last year we completely forgot about it. This year, Rob and Leanne's wedding is the focus of this weekend. Leanne spoke to me earlier about going out and getting drunk on Friday night pre-wedding.
Here's my idea:
We go out Friday, on the pretext that it's a pre-wedding party, but double it as a surprise for Bob.
If everybody thinks this is a good idea, say the word and I'll make a post that's locked to Rob and Leanne proposing the evening.