Ahh! boy trouble..?\: help..? (long explanation)?

If you really like Dylan then you should tell him. If you're not THAT interested then I would say that it's not worth it. I would tell Dylan to leave me alone and that he already has a girlfriend who really likes him and that he has to choose. If he still doesn't tell her then tell her yourself but like hints maybe when you're around Dylan. Maybe then she'll realize. If you really like Dylan and think that all of this is worth it then I would definitely tell him that if he wants you to be his girlfriend that he has to choose. I don't really know how you truly feel but I hope this helps!