Consider This:
Thank you for writing in. You are right to seek some help in this matter and share your story with Teen Central.
As a 17 year old, it is your responsibility to manage younger kids flirting with you. They may seek your attention or like the attention of an older person, but it is not appropriate to engage in this. It is necessary to stop flirting and perusing this 12 year old.
If you feel that you are struggling with managing relationships with younger people you might want to seek some professional help. Talk to an adult to see if they can help you find a counselor. Make sure you explain all your concerns to them so they can help you if needed. They will be able to sort through all the details with you.
In addition, for right now, if you find yourself seeking his attention or wanting to pursue a relationship, stop immediately and find something else to occupy your time like exercise, sports, writing in your journal, music, or movies. If you still cannot get him off your mind, talk to an adult about it.
Try finding more activities that involve kids your age. By hanging out with kids your age, you might find that you do enjoy more mature people. Get involved in activities with your school, church, local community or sports group.
Help Yourself:
Who can you talk to that can provide you support and help you seek counseling?
What kind of things can you do to prevent seeking the attention of younger people?
What hobbies or activities can you engage in to get your mind off of the younger people?