Eeep! Can a moderator please "More Inside" me? That's how distracted I am by thinking about this.

¡sí!

Gah, and I just realized that I asked about cocktail dresses twice! I'm so frazzled! I hate getting dressed for things!

Since everyone has been so helpful to me, I am going to weigh in here.
The suit looks perfectly appropriate. My only concern will be when he gets too warm. A cocktail dress is also appropriate for a 4 pm wedding. You two will look smashing, I'm sure.

I would suspect that cocktail dress and gray suit would be fine, unless you live in an area or move in circles where dressing to the nines is usual.

Oh, another thing, which may just be an individual quirk: I get weirded out if I'm wearing a sleeveless top in a church (too much time spent in Italy, I guess), so if that seems like it might be a concern for you too, make sure, if your dress lacks sleeves, that you bring a wrap or cardigan or something.

In your shoes (ha!), I would wear a dressy cocktail dress and fancy shoes, but not a full-length evening dress. At four p.m., an evening dress seems like too much.

As for MuddDude, he should be fine in a dark suit with a restrained tie. Better to wear his own suit with good shirt and tie than to rent something. Even if it were black tie, no one should so much as blink at a man wearing a nice suit.

Hang on: I dug out my Miss Manners book, and when a reader asks "Should I wear a long dress to an afternoon wedding?" Miss Manners responds by offering her best wishes... because the only person who should wear a long gown to an afternoon ceremony is the bride. Granted, the book's a bit out of date, but it looks like you're fine in a cocktail dress.

Oh, and I'll second occhi --- if you have a sleeveless dress, a light wrap is a great idea. Though I'm not religious, I don't bare my shoulders or arms in a place of worship.

I even carry a light wrap (e.g., a big but light silk scarf) if I'm wearing a sleeveless dress under a jacket, in case it's so scorchingly hot I need to remove my jacket during the interminable wait for the ceremony to begin. During my boutique days, I gave this advice to customers when outfitting them for weddings, and several came back to thank me later.

So 4pm + dinner reception is an afternoon wedding? OK. I guess that's what I was confused about.

occhi - I was planning on wearing a wrap, for the church and because it can get cold at night.

Thanks, girls. I've been trying to update my wardrobe recently, and I feel like I've got to buy something new every time I go out anywhere.

So 4pm + dinner reception is an afternoon wedding?

Well, that's the tricky bit. It's a difficult time of day, since (formally speaking and traditionally) black tie and white tie are only worn after 6 p.m. It's difficult to know what "formal" means for 4 p.m.

But if you wear a cocktail dress that feels special to you and he wears that smashing suit, you'll feel dressed enough without being overdressed, so you can relax enough to forget what you're wearing and have a great time!