Why Do Ice Cubes Stick to Damp Fingers?

An ice cube can briefly cling to a fingertip when it is picked up with freshly washed hands. The “glue” is not the cube itself, but the very thin layer of water between the skin and the ice.

Ice taken from a freezer is usually below 0 degrees Celsius. When damp skin touches it, heat flows from the water film into the colder ice. If the film loses enough heat, it freezes across tiny irregularities in both surfaces and forms a solid ice bridge. A drier finger generally sticks less strongly because there is less water available to fill the gaps and freeze. Colder ice and longer contact can allow a larger bridge to form.

This does not contradict the familiar idea that water on ice can make it slippery. The state of an ice surface depends on temperature, pressure and friction. A mobile liquid film can reduce friction, whereas water that freezes at the contact locks the two surfaces together. The crucial question is not simply whether water is present, but whether it remains liquid or becomes solid.

Freezing is a phase change, and water releases latent heat as it solidifies. The surroundings must keep carrying that heat away for the ice bridge to grow. This is why a cube straight from a cold freezer is more likely to stick than one that has warmed indoors and is visibly melting. Do not test the effect with your tongue or prolonged skin contact: very cold surfaces can injure tissue.

https://forecast.weather.gov/glossary.php?word=LATENT%20HEAT
https://www.cdc.gov/niosh/cold-stress/about/related-illness.html