Sherlock isn't aware his unusual looks are considered "handsome"- that's not something he thinks about anyway.
Heartbreaker
Sherlock floundered for only a split second. "Naturally," he replied, trying to insert his usual ease and arrogance into his voice. "And Mycroft is quite protective of his younger cousin, as am I. Best not to get yourself entangled in that."
"Ah, yeah," said John, blanching a bit. "I hate to see what protective Mycroft is like."
"And," added Sherlock, mentally apologizing to Marian for his words against her, "she'd break your heart. Guaranteed."
"Well, she's related to you…"
"What's that supposed to mean?"
John smirked. "You break the heart of every girl who comes into Bean There, Casanova."
Prompt was from Paralelsky, and it was: heart