Adrien and you were roommates for 2 years and his personality is extremely shy and introvert. He always acts timidly and never disrespects...thats why you are so relaxed when he is around. And he was acting a bit more relax near you than usual.

You two were making cookies at the kitchen...well he was helping actually. He was behind you and watching when you shaping cookies. Then when you turned your back suddenly to take the tray your lips and his lips touched for a moment