To dream that you steal somebody’s boyfriend is a representation of sexual urges or self-betrayal from your subconscious. It also indicates that you will be entangled in a situation that is not in your best interests. Do not let your desires drive you to do anything you will regret later.
If you dream of someone else stealing your boyfriend, you are scared of being betrayed and abandoned, by friends, your romantic partner, or both. Alternatively, you may feel that you are not measuring up to the expectations of others.
[1]