Place a large saute pan over medium heat and cook the bacon until golden brown and crisp, 7 to 8 minutes total. Reserve about 3 tablespoons of the bacon fat in a dish and 2 tablespoons of the bacon fat in the pan. Transfer the bacon to a paper towel-lined plate to cool.
Return the pan to medium heat and add the celery, onion, corn and some salt and pepper. Cook the vegetables until beginning to soften, 3 to 4 minutes. Add the vinegar, sugar and pimientos to the pan and cook until the vinegar has reduced and the corn is tender, 3 to 4 minutes. Adjust the seasoning as needed and set the relish aside to cool.
Place a large skillet over medium heat with about 1 1/2 tablespoons of the reserved bacon fat. In a large bowl, mix together all of the ingredients for the crab cakes, along with the reserved crisp bacon, adjusting the seasoning as needed with salt and pepper. Working in batches as needed, scoop out about 1/4 cup of mix for each crab cake and cook in the bacon fat, turning once, until golden brown and heated through, about 3 minutes per side.
As batches finish cooking, reserve them on a plate; add more bacon fat to the pan as needed throughout cooking.
Serve the warm crab cakes over warm or room temperature relish.
One of the greatest tips I ever learned was how to get corn off the cob without littering your cutting board. When cutting off the kernels, invert a small bowl inside of a larger bowl. Set the corncob on top of the small bowl and start cutting. As the kernels fall off the cob, your makeshift moat will catch them all, keeping you from chasing them down from all corners of the countertop.