Is there some sort of stereotype about young women that shelve at the library?

I'm an average looking woman and 5ft, 115llbs., & 34a-29-35. I have acne and wear gles. I'm really shy and mind my own business. Why do men flirt with me at work? I'm trying to do my job & I have NO interest in dating. Also, a lot of them are older. Is there a rumor out their about shelves that I don't know about. Do people think we're naive, easy, or something? What can I do so I can do my job? Do I scream desperation? I even had one old guy ask me to marry him and to come to his fam reunion.