Even if much of the force is alleviated by that there's still enough moving kg's left to break condoms
- which we don't even have to discuss, because there is statistics about this, and their failure rate is quite high, as said between 2% and 12% (I suppose it's a range because usage errors and quality vary).
Those two moving bodies are plenty squishy, and there's a lot of suspension absorbing forces there. There's also lubricant.