If you insert one glass into another, they can get stuck. This usually happens because the glass expands when washed in hot water, and when it cools down, it begins to shrink. Read on to learn how to gently unscrew, heat, and lubricate the glasses so they can be detached!
Steps
Method 1 of 3: Using Heat

Step 1. Find out how glass reacts to heat
Most often, glasses get stuck when they are stacked into each other after washing. When heated, the glass expands, and when it cools, it contracts. Because of this, the glasses sometimes get stuck in each other. But don't worry, as this same principle can be used to separate them. To separate the glasses, you just need to cool the inner glass and heat the outer one.
To avoid this problem in the future, take your time to stack the glasses. Wait for the glass to cool, and only then fold them into each other. If you wash glasses in cold water, then this problem should not arise

Step 2. Heat the outer glass
This method is a little risky, so be careful. Since the outer glass has shrunk around the inner one, it is this one that needs to be expanded in order to get the second one. Heat the outer glass gently by holding it under hot running water for a minute. Perhaps this is enough to separate the glasses. Otherwise, you will have to cool the inner glass by filling it with cold tap water.
Do not use ice or boiling water. Sudden changes in temperature can cause one or both glasses to suddenly burst. The glass is already under pressure, which makes the situation even more dangerous

Step 3. Cool the inner glass
If you are unable to separate the glasses by simply heating the outer glass, try cooling the inner glass as well. Thus, the outer glass will expand and the inner one will shrink.

Step 4. Try using a bowl of hot water
Pour cold water into the top glass first. Then fill a shallow bowl with hot water and insert the bottom glass into the water. Leave the glasses for a few minutes, then try to separate them.

Step 5. Carefully separate the glasses
The temperature difference should do the trick. Grip the glasses firmly, with one hand grasping the bottom of the outer glass and the other for the rim of the inner glass. Rotate and tilt the glasses to gently separate them.
If you are unable to separate them, wait for them to expand and contract even more. Leave the bottom glass in a bowl of hot water and try again after a few minutes
Method 2 of 3: Apply force

Step 1. Try rotating or tilting the glasses to separate them
Glass is rarely perfectly round, so the top glass is most likely just sandwiched between the two edges of the bottom glass. If the glasses move when you try to tilt them, then you are in luck and it will be much easier to separate them.

Step 2. Be careful
Do not use too much force, or one or both glasses may crack. If the glasses suddenly separate, they may slip out of your hands.
Make sure you have a firm grip on both glasses. Remember to dry your glasses and hands before you start. If the glass slips out of your hands, it may fall and break

Step 3. Consider breaking one of the glasses
If you are having trouble splitting the glasses, you may need to split one to avoid losing both. Place the glass on a hard surface that can be easily cleaned up later, or hold it firmly in your hand. Take a hammer and gently tap the rim of the outer glass until it cracks. This is a rather risky decision, since both glasses can crack, so do this only as a last resort.
Don't forget to collect all the broken glass shards. Safety comes first

Step 4. Try blowing air between the glasses
Sometimes a thin layer of water remains between the glasses, due to which they get stuck. Try inserting a straw between the glasses and blow into it. You will need very little air, but because the straw has shrunk, you will have to blow as hard as possible.
Method 3 of 3: Lubricate the glasses

Step 1. Lightly grease the glasses
If the glasses don't give in and you can't separate them by rotating / tilting, then it's time to grease them a little. A drop of olive or sunflower oil should be enough. If the glasses are just stuck in a few places, try using soap.
- Use the oil method in combination with heat to separate glasses that are stuck tight.
- As a last resort, try the WD-40. Spray it between the glasses. The oil will spread out on its own and you can easily separate the glasses. Be sure to thoroughly wash the glasses afterwards, as WD-40 is toxic to humans.

Step 2. Pour the oils between the glasses
Make sure that the oil seeps into the pinch points. To do this, begin to gently tilt the top glass in different directions. As you tilt the glass, the oil can loosen the clamp so much that you can separate the glasses. Moisten the glasses to help distribute the oil.
Use a thin straw or knife to push through the butter, but be careful

Step 3. Rotate the glasses until they separate
After you have sufficiently lubricated the glasses, grasp the inner glass with your dominant hand and the outer glass with the other. Rotate the glasses back and forth to loosen the clamp. At the same time, do not forget to pull them in different directions. Focus more on rotating the glasses rather than pulling them. If everything works out, the glasses should split.
Don't just try to pull out the glasses! The squeezing force required for this movement can cause the glasses to crack
Advice
The principle of this method is that the stuck glass will shrink, and the one holding it will expand
Warnings
- Work on the sink to avoid splashing.
- Do not immerse fragile glasses in hot water unless you are sure they will withstand the temperature.
- Do not hold glasses high above the sink and be careful not to drop them. Wet glass can be very slippery.