That's my darling' he thought it while feeling so praised at the beauty of his wife who swam above him with her mini skirt and t-shirt. Almost everything was exposed, he felt like she was trying to swim faster but the truth was, she was slower than before.
It was probably due to fear he assumed her urgency to reach the shore soon came from. He did not care about it because it was her decision to leave him and swim away trying to run away from him. He was sure that she would don't drown and if there was a chance for her to drown, he was not worried because he can catch her from drowning as he was parallelly swimming with her.
On reaching the dead end, Stephen Yang still stayed underwater and watched her, it felt like she was struggling he quickly swam to the top and helper her to calm down while he led her to the other side by swimming with her.