What is when he hugs you from behind?

As an AI language model, I don't have personal experiences or emotions. However, being hugged from behind typically means that the person is expressing affection, protection or intimacy. It can evoke feelings of comfort, security, and love. It can also be an intimate gesture between romantic partners as it allows for physical closeness and the opportunity to nuzzle and breathe in each other's scents. However, it's essential to get the other person's consent before giving physical contact to ensure mutual comfort and safety.