just like that

(just) like this/that

Very close and amicable. The phrase is often accompanied by a gesture in which one keeps their index and middle fingers close together or wraps the middle finger around the index finger, to emphasize closeness. Of course Jessica and Sarah are hanging out together—they're like that.
See also: like, that, this

just like that

1. Immediately; all or a sudden. And just like that, all the money I had earned was gone when I lost the bet.
2. Without any pause or hesitation. I can't believe that he agreed to lend me the money just like that!
See also: just, like, that
Farlex Dictionary of Idioms.

just like that

in just the way it happened or was stated; without any [further] discussion or comment. Sue: You can't walk out on me just like that. John: I can too. Just watch! Mary: And then she slapped him in the face, just like that! Sally: She can be so rude.
See also: just, like, that
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

just like that

1. Suddenly and, sometimes, unexpectedly. For example, The alarm went off, just like that, or And then they walked out, just like that.
2. Also, like that. Very friendly or intimate with one another. For example, Bill and his boss often see each other socially; they are just like that, or Joe and Jane are always together; they're like that. This expression is usually emphasized by the speaker's holding up two fingers and either keeping them together or crossing them to show the closeness or intimacies of the parties being discussed. [Colloquial; early 1900s]
See also: just, like, that
The American Heritage® Dictionary of Idioms by Christine Ammer.

just like ˈthat

suddenly and unexpectedly: She announced that she was leaving her job at the end of this week, just like that.
See also: just, like, that
Farlex Partner Idioms Dictionary
See also:
  • (just) like this/that
  • like that
  • too close to call
  • too close for comfort
  • crowd together
  • close to (one's) heart
  • close to your heart
  • be close to the mark
  • be close to/near the mark
  • come to a close