Drop (one's) guard phrase
The verbs "lower" and "let down" can be substituted for the verb "drop".
To stop being guarded, cautious, or alert about potential danger or difficulty.
Businesses don't want to drop their guard when it comes to investment.
It takes her quite a long time to drop her guard and open up her heart.
The verb "drop" should be conjugated according to its tense.
The expressions "drop one’s guard", in a figurative sense, seem to have only become popular in the mid-twentieth century, though the phrases have been in use in a literal sense for many years before that.
1. A type of soup that contains small pieces of pasta shaped into letters.
2. A mixture of letters which make you confused to understand, usually acronyms or abbreviations
1. I enjoyed alphabet soup when I was young.
2. The name of the organization is an alphabet soup of A.D.B which stands for Asian Development Bank.