To add to the point above: I would suggest considering the Panasonic Lumix S 35mm f/1.8 as a very practical choice for a wedding. While people usually suggest longer lenses for portraits, weddings involve a lot of group shots and environmental scenes where an 85mm is just too tight. You might want to consider this if the Seattle venue is a small chapel or a crowded restaurant. It usually sits right around your 500 dollar budget and the image quality is stellar for the price. Be careful when shooting wide open at f/1.8 tho. It is tempting to chase that blur, but if you are taking a photo of two people and they arent on the exact same plane, one of them will be out of focus. I would suggest stopping down to f/2.8 for pairs to be safe. Also, make sure to watch your shutter speed carefully. The Panasonic Lumix S5II has great stabilization, but it wont stop motion blur from people dancing or walking. Keep it fast, maybe 1/250th minimum. If you really want a longer lens but find the others too pricey, look at the Sigma 90mm f/2.8 DG DN Contemporary. It is incredibly sharp and compact, tho f/2.8 isnt quite as dreamy as the 1.8 primes. Just my two cents... weddings are stressful so keep your gear simple.

Hey there! Seriously dont panic because you picked an amazing camera with that S5II! The kit lens is fine for broad daylight but for that dreamy wedding look you absolutely need a fast prime lens. I went through the exact same thing when I started out and felt so lost. If you have $500 left you gotta look at the Panasonic Lumix S 85mm f/1.8 L-Mount. It is literally the best value lens in the entire L-mount lineup right now and it fits your budget perfectly! The reason your shots look like a phone is focal length and aperture. That 85mm focal length gives you fantastic compression which basically makes people look slimmer and pulls the background closer to them. Plus that f/1.8 aperture is huge for bokeh! Since the wedding is in Seattle you might be dealing with gray skies or dim indoor lighting and that f/1.8 aperture lets in way more light than your kit lens ever could. It only weighs about 355g and uses a 67mm filter thread, plus it has a linear motor for nearly silent autofocusing. That silent focusing is amazing for wedding ceremonies where you dont want to be a distraction! Quick tip: once you get the lens set your dial to A (Aperture Priority) and scroll that wheel until it says 1.8. It will handle the rest! Also make sure you turn on the Eye Autofocus in the settings... the S5II is scary good at locking onto eyes and it will make your life so much easier during the ceremony. Youre gonna do great and she is gonna love the photos!

Building on the earlier suggestion, you might want to consider the Panasonic Lumix S 50mm f/1.8 instead. It is technically more versatile for tight indoor venues. Be careful though, shooting at f/1.8 creates a very shallow depth of field. I would suggest this lens because it weighs only 300g and stays within your budget. Make sure to check your focus tracking settings so you dont miss the shot.

Jumping in here... Ive been super happy with the Sigma 65mm f/2 DG DN Contemporary lately. The switch to it happened because I prefer the all-metal build over the plastic Lumix primes. Just feels more reliable when bumping around a wedding venue. The 65mm focal length is a great middle ground if you find 85mm too tight. Technically, the 9-blade rounded diaphragm keeps the bokeh much smoother than cheaper glass I've used. Quick tip: lock your shutter speed to 1/250 or faster. People move more than you think and you dont want blurry faces because of motion. No complaints with the sharpness on this one, it just works well.

Came here to say the same thing lol. Great minds think alike I guess.