I have done hat with one of my sister-in-law shoes, sniffing at them and licking inside them, and then jerking off to those shoes and right after licking all my cum from them.
But even more exciting was an experience I had with a friend at my house, with my wife absent. He's in love with her feet but he's equally as gay as I am. So I stretched out on the bed naked with a pair of my wife's high-heeled flip flops. He sat in an armchair, also naked and with his penis ready for a long masturbation. I took my wife's flip-flops, started sniffing and licking the inside while I masturbated. When it was ready I discharged all my sperm into the flip flops and gave them to him who masturbated madly and started licking my sperm from the flip flops until he started to discharge all his sperm into the flip flops himself. Then he also licked his sperm and I ended up telling him that he could take the flip flops with him, which excited him tremendously and he thanked me promising that he would come with them daily until we could repeat it at my house or his with my wife's other shoes. She never came to know what happened to the slippers, as she has many slippers given to me, she thought she had lost them. I rested her by promising to buy her more.