Perhaps it is possible to talk to your supervisor/foreman/boss and explain your concerns without being judgemental. Quite often occasions, where a small innocent conflict can grow into major resentments, can be talked out under arbitration by a management representative. It is very unpleasant to work in a moody environment. You don't have to like them, but it would be so much more amicable if both parties could at least be civil. Ofcourse, they could simply be complete *rseholes, in which case you have my sympathy.