I'm sorry Isla, since it seems that this refers to you, but I 'm going to be very harsh.
First of all, a marriage that needs this type of arrangements (two times per week) is definitely wrong and useless. The husband does not have enough, and the wife is sickened. Besides that, if you need to make arrangements like these, the other side of the coin is that you'd better stick to them, no matter what. Being tired is no longer an excuse. You don't expect a store or a bank to be closed during their open hours, do you? The first thing you'll say is that "it's bad business!" See, once you go down the "arrangements" path, there is no way of stopping.
Besides which, saying things like the husband is "allowed" - or whatever the expression was - to masturbate also shows lack of insight and respect. People can masturbate all they want, and it's nobody else's business. Especially when they're in a marriage that works under a stakhanovist schedule.
So, I don't think that the husband was wrong to "pork" his wife during sleep. No matter what some whiners say about "no is no." He might've even thought that once she wakes up, she'll like it. No two people are the same. But the subsequent reaction just goes to show that the two "married" people don't know much about each other.
By the way, the choice of expression, again ("pork" ???) shows that sex is a distasteful obligation, which amounts to another reason to say this relationship is abnormal. No matter what the past is hiding. If you say sex is abhorrent, and a guy marries you nevertheless, but then finds out that despite his best intentions at the beginning, he cannot break through this barrier, he won't be around for long, and it's your duty to free him.
So the ethics involved relate to more deeper things than being "abused" in your sleep. I say again, this marriage is wrong. It's like a prison for both parties involved. You shouldn't be married if you have to schedule things like sex and intimacy. No matter what you'll try - therapy, prayer, counselling - it will be in the end just a waste of time, and most probably money. The husband might stay around for various reasons (the fear of splitting income might well be one of them, according to the psychological profile that's being drawn here), but one day he'll find somebody else.