on thin ice

(idiom) in a dangerous situation

Example Sentences:

A: How are things with you and your girlfriend?
B: I’m not sure, man. I’m on thin ice because I forgot her birthday. We might break up!

The student was on thin ice because he was absent from class too many times.

From the Blogs:

Driving on thin ice

Media:

Similar idioms:

1. spread oneself too thin
2. cold as ice