It would certainly be worth adding a new lens or two to your bag, especially if you’re shooting a wedding! And they don’t have to be expensive or name-brand, as long as you can get wide apertures like @josiahw was saying.
If you’re on a cropped sensor, then 50mm may be telephoto enough if you’re not afraid to walk up and get close when needed. I would turn your attention on wide angle first, like 10mm or something.
What you don’t want is lots of lenses that you have to constantly be changing them. Time is of the essence in wedding. Two I think is as many as I can usually handle, and if they can both be on different bodies, that’s ideal.