Is it ever acceptable to throw things in a relationship?

I got in a bit of an argument with my fiance last night. I was asking him questions about our future. I didn't lose my temper at all and maintained a normal voice as I spoke to him. He said one if the things I said to him "hit a nerve" and it caused him to get extremely angry. He cursed and threw his iPad (that I bought for him) as hard as he could against the wall and broke it and he cursed. I think our relationship is over, but he tried to make me feel guilty saying I'm all he's got and he wants to work things out. He even started crying a little and that just broke me. We have had a lot of ups and downs but I'm afraid that being physically violent crosses a line. I've never seen him like that before, although I know his father used to throw things when he was angry. Opinions?

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