Assholishly

I declared myself a wine expert, wrongly and assholishly, during my senior year of college, for a simple reason: because I was in college.

Source: wiktionary

“Sorry,” she said. “That was assholishly ungrateful. I've never had much of a filter and cancer's no mood enhancer.”

Source: wiktionary

Even if the particular rudester never learns of their ignominious star turn on the Internet, the fear of being similarly exposed should deter other rude people from acting assholishly to the rest of us.

Source: wiktionary