stick one's neck out
stick one's chin out
To do something dangerous or risky.
When I was in trouble, Paul was the only one who would stick his neck out to help me.
John is always sticking his chin out by saying something he shouldn't.
up to one's neck
Overwhelmed with; submerged in.
"During the summer season in our cottage by the lake," the Allens complained, "we are usually up to our necks in uninvited guests."