The sugar cubes melt into the hot tea.
melt into
idiomTo disappear gradually into.
As the sun set, the distant mountains seemed to melt into the dark purple sky.
The shy student tried to melt into the background of the crowded room to avoid being noticed by the guests.
- 01
butter wouldn't melt in someone's mouth
The identified person appears to be benign, mild-mannered, or calm (but with an integral suggestion that, to the contrary, they really are untrustworthy, disagreeable, or mean-spirited).
- 02
melt in the mouth
To be deliciously soft and creamy; to create a melting sensation when eaten; to need little chewing.