Hi Anna,
I found with my large pretties that they can take for ever! I have a yellow now that's I'd say half open and It's been a large bud for quite some time.

That's my experience anyways, that large ones take forever to open :(

Nikki~

Yes, I agree the biggies take a long time: lots to unpack stored in that bud! Occasionally, some petals get an early start on one side, but they should even out eventually.

Well, I am relieved to hear that, as one bud looks mighty strange right now - thanks guys!

Anna

Anna, sometimes you get a malformed bud. Last year I had a triple centered monstrosity that just didn't develop right. I might have hurt it early in the disbudding process, or it was just formed that way.
I have another that looks like it's smiling- much wider center and a bit of an oblong bloom- again, that's just Mother Nature having some fun.