I have never had a hickey but I imagine these would all be pretty good excuses.
  1. I fell off a bike
    Is this common because I just heard someone use it?
  2. Leeches on my neck
    Or other places I have a hickey
  3. That's just the way my skin is now
    Possible way to land yourself in a scientific study
  4. Just a clever use of eyeshadow
    Pretending to use makeup to pretend to have a hickey when you have a real hickey is the new using makeup to pretend to not have a hickey
  5. What are you talking about?
    Make them question their own reality. Make the questioner question themselves. Dependent on getting everyone else around you involved in the conspiracy
  6. Oh you know it's my time of the month
    I find this works to explain away other vague symptoms
  7. It's from my neck shots
  8. Selective strangling
    When someone tries to strangle you with only one or two fingers? Ineffective strangle, effective bruising
  9. I've got the good-time skin disorder
    Maybe this is just a new euphemism I just invented
  10. Neck got stuck in a small vacuum
    Maybe also just another euphemism