这个双面间谍通过秘密将两国情报卖给第三国，彻底背叛了双方。

The double agent ___triple-crossed both countries by secretly selling their intelligence to a third nation.

在间谍游戏中，他先是假装投诚，然后又暗中向原组织报告，最终三重背叛了双方。

In the spy game, he first pretended to defect, then secretly reported back to his original organization, ultimately ___triple-crossing both sides.