Act confident in front of the flirt, even if you don't feel that way. Try not to show that her behavior is bothering you. If she's brazen enough to flirt with your boyfriend in front of you, she's likely to lap up the attention if you react. Avoid clinging to your boyfriend. Trust him to do the right thing in this situation, which is direct his attention toward you.

Consider the girl's motives for flirting with your man. It is not always simply about getting a boyfriend, says DePaul University professor of communication studies Sean M. Horan, Ph.D., in the "Psychology Today" article "Why Do We Flirt?" She may be flirting to boost her self-esteem or even to make another guy jealous.

Unless your boyfriend has given you a reason to doubt him, remember that he has chosen you to be his girlfriend and he is committed to you. Tell yourself that it's actually a compliment that another girl is flirting with him. This shows how attractive and charismatic he is.

Stay calm. Getting angry will only draw attention to your behavior and cause embarrassment for you and your boyfriend. Slip to the restroom for a few minutes if you need to calm down. Call a friend and tell her what's going on. Speaking to someone you trust will help you get your feelings off your chest and keep things in perspective.

Tell your boyfriend that the girl's flirting is making you feel uncomfortable if she shows no signs of stopping. Don't accuse him of leading her on. He may not even have been aware of the flirting. It takes men around four times longer than women to pick up on subtle social cues, reports Kristina Grish in the article "When It's Time to Tame a Flirty Friend" in "Cosmopolitan." Talk to your boyfriend calmly and let him decide how to deal with the situation. If he cares about you, he will find a way to let her know her behavior is inappropriate.