While there may be individuals who are intentionally malicious, it is true that some others may not fully understand appropriate ways to show that they are interested in and flirting with someone.
When interacting with each other, it is always important that we take the time and effort to understand their preferences and boundaries, and respect those by acting in a way that is comfortable for them.
Besides respecting personal sensitivities, it is also always important to understand the context in which we are acting and what are some of the social norms or socially acceptable behaviours for that situation.
If you are concerned about crossing that line, here are some potential questions you can try asking yourself to check your own behaviour
Does it look like I am making this person uncomfortable?
Is there anything about the way I am acting that could scare or alarm them?
Am I doing anything potentially inappropriate e.g. are my actions overly-sexual for the situation or level of familiarity with the other person?
Have they indicated that they are uninterested in my advances?
Have I been continuing my attempts despite a lack of response?
Am I disrespecting the person’s wishes and boundaries (whether for personal, cultural or religious reasons) if I were to continue?
If you responded ‘yes’ to any of these questions, you might want to reconsider if there is a need for you to adjust the way you are acting around them.