Sam was perceptive, focused, and alert. But more importantly, she was Lara Croft’s best friend. Put two and two together, and whammo! You got one confused Japanese-Portuguese-American twenty three-year-old wondering why the heckie heck her cute British best friend hadn’t yet snagged herself a hunky, intelligent, bookish, adventurous, sexy, etc, etc boyfriend.
Sam’s upset ‘cause Lara doesn’t have an awesome boyfriend yet, so she forces Lara to practice hitting on her. Cue the sparks and homosexuality.