私は3Pをしたいのですが、私の配偶者はそれを望んでおらず、なぜかわかりません

I would like to have a threesome but my spouse doesn't want to and I don't know why, I told him that I would behave, that I would just let him put it in me without a condom and his friends that they do put on a condom, but he doesn't want to