Why My Girlfriend often mention to me that there are men calling her attention all the times?

She often mention that some of her friend gave her number to some man without telling her and he called and wanted to meet which she refused or she was in mall and there is a guy who comes to her and said i wanna be your friend. Is she telling me the truth or she is just bluffing to tell me that she is in demand. is she somone who is into many men at a time. I dont wanna think that way. She is 40 (If that makes any diference to your replies) and have 3 kids. We live in diferent home and dating since a year now