Fact: flirting is individual. It's unique. There is no one method that ensures success, and as writers, we need to know our characters well to find a flirting style that comes across as authentic to the reader, and achieves the results we need for our story to work.
How a character flirts will depends on these things:
Setting--where the character is plays into how they flirt. People naturally adapt to the environment and will act differently at a church picnic than at a football game. Think about the setting, and how it can define boundaries, affect mood and dictate appropriate behavior.
Confidence level--a girl or guy who is socially active and used to interaction with the opposite sex will be much more confident than someone who is inexperienced. Too, the way a character sees themselves will come into play. Someone aware of their strengths and assets will have stronger self confidence than a person who doubts their self worth. Always factor in your character's background, personality and self confidence level before choosing how far to go when flirting.
Audience--if people are watching the interchange, then the awareness of possible watchers will either ramp up the flirting or tone it down, depending on those involved. Is your character showy, or not? Do they have something to prove? Does having an audience provide the energy they need to get what they want or throw them off their game completely?
Goals--If your character is trying to determine if there is a mutual attraction, the flirting will be less direct and more tentative than if the attraction is obvious. When the goal of flirting is to heighten emotions to the crackling point, then the moves become much more intense and aggressive. Consider what the goal is behind the flirting to ensure the level of playfulness matches up.
Receptiveness--The interest level or emotional connection may not be the same for both parties. If the body language of one character suggests they are not as engaged (moving back, looking away, fidgeting) as the other hopes, then flirting style and intensity level will need to change in order to keep a connection.
Flirting is all about body language and knowing how to read it. Here are some flirty moves to get you started!
Smiles (is there anything more attractive than a smile?)
Eye contact (not constant or it's creepy, more like a magnet pull of repeat contact)
Light and brief touches
A light squeeze of her hand
Runs a knuckle down a forearm
Drapes an arm around her shoulders
Places a hand on the small of her back
Steers/guides with light touches, arm pulls, playful nudging
Touches an item she's holding (tugging, tapping his pencil against her notebook, etc)
Notices and verbalizes approval in what she wears or how her hair is styled
Offers flattery, compliments
Suggests to do something benign together (get a drink, walk the same direction, find a place to sit, study together some time, get some fresh air, etc)
Jokes, teases, engages in small talk, banter
Agrees with her opinions
Downplays her compliments to him (showing modesty)
Does a double take of her in order to be 'caught looking' (but doesn't stare like she's meat)
Holds eye contact slightly longer than he normally would
"Accidental touches" (bumps her leg with his, brushes her hand, shoulder, etc while reaching for something)
Mentions something he's noticed/remembers about her (something in their mutual past, something he saw her doing before approaching, etc. This is to show she is memorable)
Watches her lips
Says things that have a double meaning/suggestiveness
Walks past more than once
Turns head to look back at him
Moves closer to him in the room/area
Shakes back hair
Uses the eyes and lashes to express and communicate
Asks questions about his interests
Gossips to friends, but eyes are on him
Touches lips (Lips are sensual) IE: biting down while smiling, wetting lips, applying gloss, bringing a drink cup/glass to lips with eye contact
Leave friends to either stand alone and offer an opportunity to be approached, or will directly approach him
Playful touches (fiddle with zipper, turn his wrist to pretend to be interested in the time, etc)
Shows interest or handles something of his (asks to see his play list, asks about his phone, slides a book out of his grip to look it over, etc)
Plays with her hair during conversation, drawing his attention to it
Lets him know that something he says is new/interesting/unusual/or positive in some way
Agrees with his opinions, thoughts, observations
Varies the timbre of her voice to keep him listening (whispers, suggestive tone)
Uses hands to accentuate features (a narrow waist, pulling long hair over one shoulder, fiddling with necklace to draw attention to neckline, etc)
Leans or steps closer
Places a hand on arm
Asks about his friends, job, talents (if she knows a bit about him)
Asks for his opinion or for help with something
Exudes high energy, fun
Acts coy, shy or playful by tilting the head, side-long looks, and using different types of smiles
Accepts compliments gracefully
Listens closely, and acts on clues in conversation to his likes, dislikes, interests, beliefs, etc
Touches his knee or arm to emphasize a point or while laughing
If in a skirt, places a hand on knee or slowly crosses her legs to draw attention to them
Compliments his scent by leaning in with a smile and asking what cologne he's wearing
Gets 'caught' looking him over and enjoying the view
Mirroring his movements (if he leans in, she does the same, etc)
Points her body toward him (sitting or standing)
So...what are your character's favorite moves?
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