Hey all! I've been away for a long time but here I am again. I need advice!

I'm officiating a friend's wedding on September 5th. She's wearing a traditional white dress, he's wearing a navy blue suit, bridal party is wearing a variety of darker neutral-ish colors. I asked about wearing black, she said that sounded great. Which is good because I usually wear a lot of black! But I don't really have anything that is up to snuff for wearing to an occasion such as this. I'm not even sure what the dress code I'm looking for is, since a wedding guest could wear a party dress but I want to look... slightly more dignified?


I'm not sure whether to go with a dress, or a top/pant look, I'm thinking of getting Hasbeens/Lotta's because I want them and they would go with the bride's general aura...

Any advice? I'm looking for specific links if you have 'em!
I generally like looks that are slim fitting, like skinny pants, slim dresses, and with my particular body type whatever dress/top I wear needs to define the part of me right under my breasts otherwise I look wonky (I'm a 36E? I think...)

Thanks all!