Fortunately, it happened underwater so the audience didn't see that they accidentally kissed. Not only they were seen as brothers, but only a few people knew that they weren't blood-related.
But, even so, that isn't an excuse to not feel guilty about it, Qian Meng! Qian Meng scolded himself in his mind. The heat on his face also receded because of it. Qian Meng already knew in his heart that he loved Qian Jue, secretly. He realized it when they were still young. But, he knows that Qian Jue doesn't feel anything towards him aside from treating him as a sibling.