What are signs a man is obsessed with you? Body langauge or just by what they do?
Most Helpful Opinion
Obsessed? You'll know because he'll talk about you to other people. Contrary to what is popular pseudo-psych males talk a lot more about whom they like and specifically focus on that person and they do it a lot so if you're not painfully oblivious you'll hear about it.
Other than communication obsessed people will pay extreme attention to detail in relation to you and will be fairly obvious of their obsession regardless of shyness or not even going so far as to "closet" aid you in various ways trying to be part of your life by doing kind little things or helping you without your permission behind the scenes as appropriate ranging anywhere from putting a good word in for you here or there to helping you in your studies and at work to succeed in whatever your endeavors are without being intrusive.
Honestly at that point body language is pretty pointless but then again I presume you really meant obsession versus interest as the two play out entirely differently.