Maybe you are aware that someone is interested in you, and you don't want to make the feelings seem mutual. Or maybe you're in a relationship and don't want to look like you want to cheat. Sometimes you just need to avoid flirting. It takes a lot of self-awareness and self-control, so be prepared!
Steps

Step 1. Don't share personal things with this person
Don't tell him about your home issues or your personal issues. Trust is something that happens between close friends.

Step 2. If this person starts flirting with you, interrupt them
She pushes you to do it, don't do the same. Ignore it and talk about a general topic instead.

Step 3. Do not look the person in the eye
Focus on something else while talking to them, and if you are looking at the person, don't stare at them, but don't appear nervous or scared. Look like you're almost bored, but don't be rude.

Step 4. Suggest a friend to come
Often times, if a friend feels that you are uncomfortable, they will intervene.

Step 5. Go
Politely tell her that you need to go somewhere else or that you need to go talk to someone.

Step 6. Talk about your other dear boy and girl friends
Make sure you know how to incorporate this topic into the conversation, as this tactic can be very offensive if done awkwardly.

Step 7. Use reserved body language
Cross your arms and stand away from the person.

Step 8. Ignore emails, texts, and calls that are outside of work or the office

Step 9. Beware of those around you
Avoid giving the opportunity to another person to see what they are not supposed to see.
Advice
- Don't be rude to the person. Show her big obvious signs of friendship so that she will be notified exactly.
- Don't give him friendly kisses or anything like that. Make sure she knows about your dating situation and how you feel about her.
- If you can do it smoothly, tell the person that they are like a brother / sister to you. No one likes to hear this, however it clearly gives the other a sign that they are valuable to you, but that you are not romantically interested in them.
- Tell the person you're not genuinely interested if they really bothers you.
Warnings
- Be careful when you assume that someone is interested in you or is trying to flirt with you. It's quite offensive to use these methods on someone who is just trying to be friendly.
- Do not touch the person. Touching her is a main sign of flirting!
- Don't ask too many questions … You know you don't have to appear to be interested.
- Don't ask too many privacy questions… You can tell how plentiful the meals or cups of coffee are, in places (that you have visited with another loved one) where you enjoyed the coffee and the food served to you …
- Whatever you do… DO NOT give this person a compliment!