Question: why is akward to be in the same room with an exlover? 

Answer: You shared a relationship with that person that is like no other.  You know each other in a different way than anyone else ever will.  Former lovers and future lovers will not even experience the same relationship because, I assume, most of us evolve with each intimate relationship.  Plus, you have the added awkwardness of other people around you knowing you 2 as a couple so it is mildly wierd for them as well.
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