I'd genuinely consider this a dealbreaker on both sides.

For me, if this was a problem for you I'd consider us pretty incompatible. It would be the end of the relationship hard stop, nothing to talk about.

And from your perspective I can see how you feel violated and would consider that, equally, a dealbreaker.

These kinds of things should absolutely be discussed before you start sleeping in the same bed, because this is very much a grey area where I can see a pretty easy 50/50 split. For some people this will be assault, for others it'll be the perfect way to wake up.

It's something that can be a major compatibility issue, yet it rarely seems to get the discussion it needs until there's a conflict.

If you consider this inexcusable you might have empathy problems, or you might be very naive, or you might have a history of trauma that is make it hard for you to see clearly. It's always worth examining where our feelings come from - not to change them, necessarily - but so that we can better understand ourselves.