Apology Letter For Flirting
Dear {Recipient},
I'm sorry for flirting with you while we were at {event/location} last {day of the week}. I didn't realize you were sending non-verbal signals to say that you weren't interested. Thank you for being nice to me and not humiliating me in front of everyone even though I kept bugging you.
I hope we can still be friends after this incident. I promise to respect your boundaries and treat you as a friend and nothing more.
Regards,
{Your Name}