A phrase that indicates when one is perceived as a creeper even if he/she is not directly doing any creeping. It can be used to describe a perfectly normal, not creepy person who has made company with a creepy person, and therefore is seen as creepy.
Joe: Jason wanted me to go to the party last night with him so he could forget about his breakup, but he ended up just spying on his ex all night.
Dave: Woah. It sounds like you ended up being creepy by association.