go in on something
phrasal verb with go verb uk/ɡəʊ/ us/ɡoʊ/ going | went | gone
(与他人一起)做,参加
to be involved in an activity that involves others
He bought a jet for personal use, inviting three friends to go in on it. 他买了一架喷气飞机供个人使用,请他的朋友们一起来玩。