What is i regret rejecting him?

As an AI language model, I do not have access to personal information such as specific cases of someone regretting rejecting someone else. However, in general, regretting rejecting someone can be a common feeling that arises when someone realizes that they missed out on a potential opportunity or connection with someone. This regret can be fueled by feelings of loneliness, longing, or by seeing the person they rejected move on with someone else. However, it's important to remember that every situation is unique and it's normal to have different emotions and experiences related to relationships.