"Umbridge." Harry said with complete sincerity. He hated the woman, and he knew that almost everyone he knew hated her as well. She was a disgusting frog-like toad of a woman that was completely unattractive and the perfect mood killer. When he was fifteen and things were just hitting their most embarrassing with Harry, Umbridge came into his life and kept his sexuality in check.
"When you start to think about sex a little too much, think of Umbridge doing sexy things and you'll be completely turned off. Like, think of her in a pink tutu doing ballet, or think of her in lingerie. It's completely unattractive and will kill any hope of an erection within seconds."
He shuddered and took a long drink from his ale. "I feel dirty thinking about it now."