I think you're old enough now to stop playing the blushing school-girl with older men, especially those in positions of authority above you. If you want to make friends with the co-worker who is close to your age, and not in a position of authority over you, I see nothing wrong with that, although if your friendship ends you'll still be working at the same place. But allowing the older men to form unhealthy attachments to you in the workplace is just not cool and it isn't good for you professionally or personally. Sounds to me like your boss has been test-driving a sexual affair with you in his mind. Unless your artwork is related to your job, keep it at home.