When $young_female_coworker is having a conversation with you at your desk, please be more careful where you rest your distracted gaze while listening to her.
Professionally speaking, her crotch is probably not the most appropriate location.
Yes, yes, I know, we've seen the pair of you together and it's all very sweet, but not during work, hey?
Best regards
Me
(Edited to address
pir's first comment) 