grow apart
phrasal verb with grow verb uk/ɡrəʊ/ us/ɡroʊ/ grew | grown
(also grow away from someone)
（通常因为失去共同的兴趣或愿望而）逐渐疏远，渐渐产生隔阂
If two people in a close relationship grow apart, or if they grow away from each other, they gradually begin to have a less close relationship, usually because they no longer have the same interests and want the same things.
There was nobody else involved - we just grew apart. 没有任何外人插足，我们只是渐渐疏远了。