Stoop to
Definition 1 of 2
Pro Tip 1/3Negative Implication
Using 'stoop to' suggests the action is immoral or wrong. 
She wouldn't stoop to spreading rumors.
Pro Tip 2/3Figurative Use
'Stoop to' is often used metaphorically, not describing physical action. 
He refused to stoop to their level of pettiness.
Pro Tip 3/3Expresses Reluctance
Indicates reluctance to do something against one's principles. 
Despite the pressure, I won't stoop to cheating.