I've referenced schema like this

var User = new Schema({
    following:[
            {
            type: mongoose.Schema.Types.ObjectId,
            ref: 'User'
        }
],
    followers:[
        {
            type: mongoose.Schema.Types.ObjectId,
            ref: 'User'
    }
]});

Think about A user follows B user. user A schema will be like this:

{
following[{User B}]
}

When i remove user B, User A still contains User B as a following user. How do i fix this?