Dressy tops you can breastfeed in, do they exist?

[Pannacotta]

If so please can you help me find one! I have a Christening and two weddings in the next 6 weeks and while I have lots of posh skirts I only have jersey tunics for my top half...
I need a top which I can pull up to feed in, dont get on with the "whipping a tit out from the top" thing IYSWIM!
TIA...

I've seen some good suggestions for a vest-style top with a cardigan over as being quite easy to bf in, but not sure this counts as dressy enough.

vest top with wrap over on top. pull down wrap over and pull up vest.

JN it also depends on finding a loose enough vest top (which I havent), also would prefer sth bit dressier so I dont have to wear a cardi/jacket on top if it is hot.

ANy other ideas?