Buffy knocked on Xander's door and impatiently waited for an answer.
She was sure he was home. He'd told Willow he had the whole weekend
off of work and wanted to spend it resting after putting in some
serious overtime. Even though Spike was now staying at his place,
she was sure Xander was there too. He was too stubborn to allow
Spike's presence to drive him away from his own home when he wanted
to be there.

No one answered the door so Buffy knocked again. Spike, at
least, should be there. It was broad daylight. She didn't care if
she had to wait him up. She could at least get him to let her in
to wait for Xander.

No one answered the second knock, but Buffy was sure she heard
movement from inside the apartment. "Spike!" she called. "I know
you're there so let me in!"

There was a definite scurry of motion inside but no one came to the
door. Buffy grabbed the knob, ready to break the lock to get in.
She'd pay Xander for the damages. It would be worth it to teach
Spike a lesson.

She twisted, and the knob turned easily. The door was unlocked.
Buffy shoved it open and stepped into the apartment, then stopped
short in shock. Spike was there, but so was Xander. The two
were tangled on the couch in a highly complicated sexual
position and their faces were turned to her in twin looks of
stunned horror.

Xander turned to Spike as much as he could in his pretzel position.
"I TOLD you to lock the door~"