your part of a team sara and if your boss thinks its important that hatchets are buried, you must do it or suffer the consequences if the boss has to choose between you. It's part of the job to gel with the team rather than split the team with some siding with you. It is a hard pill to swallow but you must at least be civil.
Smile & tell your boss you agree, shake hands even - if you must, (thinking of your salary). Civility you can show (for the teams sake) but more than that keep suppressed.