All her customers whom I always chatted with were very friendly to me.

I loved dinnertime because the kitchen was always full of relatives and the customers that my father had invited to dinner

위 두문장에서 왜 목적격 관계대명사인데 생략 할 수 없는것이죠?

헷갈려서 머리가 터져 버릴 것 같아요.ㅠㅠㅠ

고수님들 알려주세용!!!!!