Well, i certainly wouldn't have thrown water, but i'd be just as angry as you.
I do not agree with porn, at all. To me, if you are in a relationship, you shouldn't be looking at anyone else in a sexual way. Of course walking down the street you'll notice if someone is good looking, i'm not saying you can't feel any attraction to anyone else ever, but you shouldn't go looking for someone other than your partner to look at sexually. To me that feels like cheating, maybe it doesn't to the majority, but to me, it does.
I am very clear about my feelings about porn before i enter a relationship. If they aren't willing to not view pornographic videos or images, a relationship between us doesn't happen. If i find out later on that someone who said they understood, agreed not to to watch/look at it, and got into a relationship with me, was indeed watching/looking at porn, i'd feel very betrayed. I would feel cheated on, and thats not a choice to feel that way, it is just how i feel, so it isn't unreasonable, especially as i would have been very clear about it before the relationship started. It would majorly negatively affect my self confidence, my trust in them, and how stable the relationship was. I'd react badly, i'd shout, i'd cry, but i wouldn't assault them. I'd not want them near me so i would go to a different room, and no way they'd be sleeping in the same bed as me that night, but i wouldn't throw someone out unless it was my home they were in, not ours.