When you discover that your best friend really likes your boyfriend, it’s normal to feel jealous. How strong your emotions are may depend on whether your boyfriend likes her back. Treating them both with suspicion can create more problems, so carefully consider your response to avoid driving him away and destroying the relationship with your best friend.

Jealousy is a reaction to a perceived threat to your relationship, according to psychotherapist Clifford N. Lazarus in “Taming Jealousy” for Psychology Today. Just because your best friend likes your boyfriend doesn’t mean that she’s trying to steal him. It's a breach of ethics to steal your best friend's boyfriend, so give her the benefit of the doubt if you can. If your boyfriend isn’t romantically interested in her, the threat to your relationship could be negligible. You can stand down when there is no active threat to the relationship. Let your best friend know that you have a keeper and acknowledge her good taste in men. Be attentive and loving to your boyfriend and let him know how special he is. Remind yourself that your relationship is in no danger.

Have a chat if either your best friend or boyfriend are ruffling your feelings with their actions, suggests Lazarus. Ask your best friend to stop flirting with your boyfriend and let her know how it makes you feel, for example. Identify the emotions for her and let her know that you’re getting hurt. She might not realize how her actions are hurting you. In a similar fashion, talk to your boyfriend about flirting back or egging her on for the attention. In either case, don’t cast blame for your feelings. State what you see as unemotionally as possible and ask for it to stop.

When most or all of the threat is in your head, deal with the issues that inflame the jealousy, such as fear of betrayal because of a failed past relationship or poor self-esteem. Don’t compare yourself to your best friend, advises psychologist Melanie Greenberg in “The Psychology of Scarcity” for Psychology Today. Practice gratitude for your awesome boyfriend and the wonderful things in your life, such as your child, job and your circle of friends. Let your best friend know you appreciate her friendship and express your hope that she finds a relationship that is awesome for her. Tell your boyfriend how happy you are with him and list his best qualities. If you can't still the voices alone, seek professional help.

If your best friend and boyfriend are betraying you, you have a bigger problem, acknowledges therapist Helen Fisher in “Jealousy -- The Monster” on Oprah.com. When confronting them doesn’t stop the behaviors, decide whether to maintain a relationship with either one of them. Eliminating one of them from your life could fix the problem. Hopefully when they understand what's going on, they will take steps to preserve the relationships with you and put an end to your discomfort.