There comes a time when the man you have always regarded as a reliable friend begins to give you ambiguous hints of a close relationship. Your friend may suddenly be inflamed with an ardent passion for you.
Your refusal should not be based on his shortcomings. Don't tell him he's not smart enough or sexy enough. Be diplomatic. If you have a presentiment that a proposal for a close relationship will come in the near future, before it's too late, change your tactics.
The main rule is no flirting. Daring outfits, bright lipstick, flirty and languid look are a signal for a man that you are ready for intimacy. Therefore, try to be more modest. Maintain physical distance. Clarity, composure and directness in a relationship does not contradict the rules of etiquette.
You can explain to him that you, for example, are not free and remain faithful to your One and Only. It doesn't matter if you are free at this moment or not. A man with an adequate psyche will understand you. Such an attractive and intelligent woman simply cannot be alone.
Refusal can be motivated by family traditions of upbringing, that before the wedding you are no, no. If it happened that after an extra glass of champagne at a corporate party, your friend is ready to go on the offensive, and you do not have "this" in your plans, you can refer to "medical circumstances".