Oh, I see. It must be ~はごめんです／ごめんだ. Yes, it's similar to 遠慮する. But your emotion that you want to avoid it sounds more stronger when you use ~はごめんです／ごめんだ. （例） A：ねえ、来週のパーティにDさんを招待する？ Hey, are you gonna invite D-san to the party next week? B：うーん、あの人、お酒を飲むとすごく暴れるでしょう。前のCさんのパーティでも、それで大変だったじゃない？あんなトラブルはごめんだから、あの人は呼ばないつもり。 Well, he behaves pretty violently when drunk, you know. They had a hard time because of his bad behavior in C-san's party last time. I don't want such a trouble for me, so I'm not gonna invite him. ===== ごめん（なさい）for apology is used only for your own doing. D: あばれてごめんなさい。テーブルを壊してごめんなさい。けがをさせてごめんなさい。 Sorry for behaving badly. Sorry for breaking the table. Sorry for making you injured.

sorry = ごめん or more politely ごめんなさい I have never heard "ごめんです" much.

= sorry