Aurivor Replacement Ear-Pads Cushions for Bose QuietComfort (QC) 35 35ii 25 15 2 and More Headphones, Upgraded Covers with Soft Protein Leather, Reinforced Sealing, Optimized Memory Foam (Brown)

Personally, I would recommend replacing the ear pads. For example with these: Aurivor Replacement Ear-Pads Cushions for Bose QuietComfort (QC) 35 35ii 25 15 2 and More Amazon link If you want to repair, I would get one of those clear, waterproof bandages such as Nexcare™ Tegaderm™ Transparent Dressing H1626-06-CA, Waterproof, 4 in x 4 3/4 in (10 cm x 12 cm)Amazon link Elastoplast Second Skin Protection XL Hydrocolloid Patches, Ultra Thin and Flexible Amazon link And then glue it very lightly at the edges using a flexible CA or silicone glue like Flex Super Glue, Liquid CA, Cyanoacrylate Adhesive Amazon link