Be in bad, poor, the worst possible, etc. taste
Definition 1 of 1
Pro Tip 1/3Cultural Sensitivity
Understanding what may offend different cultures can prevent using the phrase poorly. 
Commenting on someone's traditional attire in a negative way is in bad taste.
Pro Tip 2/3Emotional Impact
Using this phrase implies that something is not just wrong, but it also offends or upsets. 
Laughing about a tragic event is in the worst possible taste.
Pro Tip 3/3Subjectivity
Remember, whether something is in poor taste can vary between individuals and groups. 
Her painting was seen in poor taste by some, yet deeply meaningful to others.