I have to admit this isn't a topic that I have mastered myself, and no matter what, there are going to be blurry lines! Although, I think it is a topic that is extremely relevant for all girls and guys...no matter what age!
What impression are you giving?
Are you giving the impression that you are interested in a guy, but you really aren't? This can lead to hurt on both sides, and also break the friendship that you may currently have. Being BEST friends with a guy can unfortunately be dangerous... if you don't end up dating them, then in many cases the friendship can end badly so be aware and intentional about where the friendship is heading (took me a few times to learn this). Although, building a friendship with a guy before you date is a beautiful thing, but be aware of both emotional and physical boundaries in the process! Flirting is tempting because it serves as a quick way to get to know someone and gain a level of comfort with them that would otherwise take longer. 1 Cor 10:23-24 “I have the right to do anything,” you say—but not everything is beneficial. “I have the right to do anything”—but not everything is constructive. No one should seek their own good, but the good of others." I think this verse fits perfectly because when we seek our "own good" we are putting ourselves first and quickly loose sight of the consequence of our actions, and how will affect another person.
What are your intentions?
I'd say this may be one of the all time biggest offenders (has been for me atleast). I can't talk for the guys as much, but girls can be flirty just to get "special attention." Maybe you are sick of being looked at like a friend and you want attention that makes you feel attractive for the moment. The scary thing is... when you get attention purely from flirting... then you are building that relationship off of something that is completely surface level. In some cases there is alot more there and flirting is a way to show you are interested... so ask yourself, are you? and if so, for the right reasons? Proverbs 31:30 "Charm is deceptive, and beauty is fleeting; but a woman who fears the Lord is to be praised." Building a lasting relationship on meaningful things, like talking about how you see God using you in the future, THAT will produce a lasting relationship. Let their attraction to you come for the right reasons...that type of attraction will only grow.
What outcome do you typically see?
If your still not sure whether you need to make the shift from flirty to friendly then look at the results of your actions. Whenever you interact with guys, are they asking you out a few days later? or are you able to build a friendship with them before you are asked any big questions? Luke 6:43 "For no good tree bears bad fruit, nor again does a bad tree bear good fruit." If you have the right intentions and do not use your body or the way you dress to get attention then good will come from that! If you choose to use these surface level ways to get attention then in the long run it will not produce good outcomes, and will in turn draw you further from God. If you respect yourself, and recognize the worth you have in Christ, then you will begin to realize you should not need to dress or use your body to gain worth in a guy's eyes.
Hebrew 13:1 "Keep on loving one another as brothers and sisters." This is the best way to get a know a guy in a "friendly" way. Ultimately, lasting joy and fulfillment is not going to come from some guy giving you attention, it's going to come from building a relationship with God. I know that may sound "cliche," but before you dismiss the truth of that statement, try it out for yourself. Spend time with God (click here to learn how), and learn to experience joy that is above your circumstance!
I know this can be a controversial topic, because each person has different experiences, so if anything I said was confusing or you don't agree feel free to send me an email for clarification, I'd love to hear your thoughts! Otherwise, comment bellow! <3