Sherlock lay back in the bath watching John swim, playing sea monster with a toy ship he had demanded Sherlock get after watching The Little Mermaid, but his mind was focusing on his current case. He didn't see how the murderer had gotten out the house with the weapon, without alerting anyone. He was frustrated with the lack of answers and wouldn't have had a bath in the first place if John hadn't begged. Sherlock could never resist John's begging face. John was happily splashing and squeaking and it was getting so hard to think. Sherlock didn't have the heart to tell John to be quiet. To think properly Sherlock took a deep breath and sunk bellow he water, to think in the calm, underwater world.
John was happily playing at the other end of the tub. He had just sunk the ship, claiming all lives aboard, when the water sloshed around. He looked to the over end of the tub and saw that Sherlock was under the water. John swam over to where Sherlock head was and dove under to watch the man. After a minute John was worried. He knew Sherlock couldn't breath under water like he could, Sherlock didn't have gills. A few more seconds went by and John made his decision. He had seen this done on the television when someone had stopped breathing. John swam down to Sherlock's face, placed his hands on Sherlock's cheeks and kissed Sherlock.
Sherlock was surprised to feel lips on his and shot up sitting up straight in the bath, in the process throwing John into his lap. He looked down and was surprised to see John was crying. Gently, minding his tentacles Sherlock scooped John up and brought him to face level. John was still sobbing, his tentacles wrapping around Sherlock's hands tightly.
"I thought…I thought….I thought…." John sobbed, not being able to finish, taking deep gulps of air.
"What John" Sherlock kept his voice calm, he had never seen John cry so much before,
"I thought you were dead" John wailed, gripping tighter with his tentacles and wrapping his arms as much as he could around Sherlock face and broke down in tears.
Sherlock hummed, rubbing his finger up and down John's back until the sobs had subsided, but he was still sniveling.
"I'm fine John, everything is fine." He murmured and John sat back.
John glared at Sherlock and rubbed his eyes. He tightened his grip on Sherlock so it was hurting.
"WHY, WHY DID YOU DO SOMETHING TO SCARE ME LIKE THAT" John yelled pushing himself up.
Sherlock winced at the grip of the tentacles but stayed calm.
"I'm sorry John, I was thinking about the case I'm working on, I dint mean to scare you" Sherlock told him.
John relaxed his grip on Sherlock but still looked angry. The man had just scared John to death for a stupid case. John thought he was dead and …. John's mind froze when he felt Sherlock press his lips against his head.
John looked up at Sherlock confused.
"Why did you do that? I can breathe" John questioned.
Sherlock looked at the small hybrid; honestly he did not know why he had kissed him. It had nothing to do with his angry face being cute. No of course not. Still it took a few seconds to fully process what John had said.
"That was a kiss, and what does breathing have to do with it?" Sherlock asked.
"I was on the television, that you put your lips someone else's to make them breathe." John told Sherlock.
"No, not exactly, what you're thinking of is CPR, which is where you breathe into another person's mouth to get them breathing again. What you did was a kiss." Sherlock told the now blushing John.
"Oh," John whispered and then bolder "so why do people kiss?"
This time it was Sherlock who blushed. Relationships were never his area, but John was different.
"A kiss is usually a sign of affection, usually love. Sometimes they are exchanged between friends or family, but mostly they are between two people who love each over romantically." Sherlock told him.
"You kissed me, does that mean you love me" John asked, not meeting Sherlock eye and retracted his tentacles.
Sherlock didn't even pause, replying automatically "yes John, I love you"
John looked at Sherlock and beamed. "I love you too Sherlock, I love you a lot"
Sherlock smiled and relaxed back into the bath placing John on his chest.
"Where did you learn that a kiss made someone breathe again?" Sherlock asked
"On the television" John replied cuddling up to Sherlock's chest.
"What were you watching?" Sherlock asked stroking John absentmindedly.
"I was watching one of those DVDs you got me. It had an evil queen who made a pretty princess stop breathing and then a price came and he kissed her and she breathed again. There were also seven small men with beards and they put the princess in a glass coffin…."
John continued to babble on about the film and Sherlock groaned to himself. He was definitely going to have to explain to John about the differences between reality and Disney movies.
AN: The average person can hold their breath for around 30 seconds. However trained swimmers can train themselves to hold their breath for 2 minutes or more. I believe with the amount of danger Sherlock could get into, he would have trained himself to hold his breath for long periods of time which is why he can be safely underwater for a period of time.
Also I believe that after watching 'the little mermaid' John would have loved it so Sherlock would have gotten him a lot more Disney DVDs like Snow White. He just loves to spoil John.