Phrase: No rest for the wicked.

Aslaamualaaikum

If A Muslim was working away hard and was given more work. A Christian colleague said the following phrase to him:“no rest for the wicked,”

(“no rest for the wicked,” which implies that the devil will not allow his followers to rest from their evil doings.
1. literally, Eternal torment in hell awaits sinners.
2. humorous, People who are wicked must work harder than normal people.)

The Muslim just laughed and verbally said, “I know”. Although the Muslim does not follow the shaitaan.

Does the Muslim lose his imaan by laughing and saying any of the above or by verbally saying the above phrase?

Jazakallah