You may believe that you don't need to be loyal to the one you are flirting because it is only a light-hearted flirt; you don't have any obligation toward the person who is interested in you and to whom you showed interest.
However, if you wish to have another kind of relationship you must be loyal.
What if the man or woman who wants you is following you? What if he or she notices that you flirt a lot with several people? If you feel attracted to someone and expressed your interest and if it was reciprocated, you already have a kind of relationship.
You are already somehow compromised, unless you like to flirt without any intention other than to have some fun.
How would you feel if you noticed that kind of behaviour in the person you love? Especially if you are attractive and you have many admirers, you have to care about being loyal to the one that interests you more; otherwise, you may lose them.
Never play with their feelings trying to provoke jealousy because this is very painful and it may be completely different from what you wish.
Instead of feeling jealous and trying to make you pay attention to them, they may abandon you completely and care for somebody else who does not disrespect them the way you do.
You must behave with others the same way you want them to behave with you, especially with the most important person in the world for you.
Don't hurt them or be futile because you will be judged by your actions.
If you only flirt you don't have the chance to explain anything to the desired person and all the impressions they have about you are taken as revelations about your character.
They will admire you and feel safe with you if you show them loyalty and respect, even though you have only suggested a relationship, which is not even serious yet.
This is the indispensable attitude you must have if you do want to have a serious relationship in the future!