run off with
phrasal verbrun off/away (together) | run off/away with somebody
to leave home, your husband, wife, etc. in order to have a relationship with another person 与某人私奔 He and the next-door neighbour ran off together. 他和隔壁邻居一起跑了。 He ran off with the next-door neighbour. 他和隔壁邻居私奔了。
run off with something