Set rules. This doesn't mean that you make a list of things that he can and can't do. Instead, communicate what you expect from him, and ask him to do the same for you. Agreeing on rules for flirting can keep over-heated emotions at bay and help you both understand what the other person views as acceptable behavior, according to professor of psychology Michael Karson on the Psychology Today website. For example, tell him that you don't want him flirting with your best friend or ignoring you to flirt with another girl in the room.
Build a healthy sense of trust. If you feel secure with your boyfriend, knowing that he isn't keeping secrets or acting sneaky, you'll have the trust you need in him to handle his flirting. Sharing your most intimate thoughts, feelings and hopes with each other can build a sense of closeness and facilitate trust. When the two of you truly trust each other, you'll have security in your relationship. When he flirts you'll know that, although he's talking to another girl, it's really you that he loves. Remind yourself that flirting isn't the same thing as cheating. He may just have a naturally flirty personality or his family or cultural background may consider this type of behavior acceptable.
Speak up and share your feelings. It's possible that your boyfriend doesn't even realize that he's flirting or that his behavior is bothering you. For example, the two of you are out at dinner and you view the way that your guy is speaking to the waitress as flirty. Tell him that his warmth toward her is making you feel uncomfortable. He may think that he's simply being polite toward her.
Walk away when the flirting goes overboard or he refuses to take your feelings into consideration. If the flirting is bordering on -- or has moved into -- actual cheating, it's time to consider moving on. Confront him calmly and ask him if he can respect you and your relationship.