When we clean the cups, the cups may overlap. If you pull out with force, the glass will often break and hurt your hands, and the bottom of the racket will become tighter and tighter due to inertia.
Let me teach you that you can easily separate the nested glasses without breaking them. If the glasses overlap after washing, you must not use brute force. At this time, just soak the outer cup in warm water, pour the inner cup into ice water for a while, and then pull it out while turning. The principle of heat expansion and contraction can make them separate.