Using 'vulgar' implies that the behavior or language is offensive to most people. She stopped talking to him when he made a vulgar comment.
Pro Tip 2/3
Cultural Sensitivity
What's considered vulgar can vary greatly between different cultures or social groups. His joke wasn't considered vulgar in his country, but it offended everyone here.
Pro Tip 3/3
Not Workplace Appropriate
'Vulgar' often refers to language or actions that are inappropriate in professional settings. His vulgar stories were not suitable for the office environment.