I never said assuming was ok.
I said that it can be without malicious intent.
Intent is absolutely irrelevant.
If a man genuinely believes I will enjoy him having sex with me when I am passed out drunk, is it ok?
If a man hears a woman say she's a lesbian and thinks 'if I have sex with her she'll enjoy it so much she'll realise she's not gay' and then rapes her, does it matter that he didn't have malicious intent?
NO. Intent has nothing to do with it. It's actions that matter.
The absolute best thing that can be said about OP's partner is that he didn't care what her boundaries were. That doesn't make what he did ok.
If you started dating my husband, he might be shocked at how different the relationship boundaries are and may make a few mistakes before settling into a routine with you.
He won't 'make mistakes'. He will either have enough respect and decency to ask in advance if I want to have sex with him or engage in specific sex acts, or he will be a rapist / abuser.
Is this not forgivable? Would you not just tell him what you don’t want and see how he adjusted? Or would you scream abuser and leave him at the first instance?
Rape and abuse are not forgivable and I would leave the moment somebody engaged in a sex act with me without asking my consent first.
It is every person's job to ask for consent before engaging in a sex act. It is NOT acceptable to do whatever the fuck you want and then apologise after if the other person didn't want it.
You are literally legitimising the behaviour of rapists. Men who take advantage of women hear views like yours and think 'so it's ok that I had sex with her without asking, because I didn't know in advance that she wouldn't want it.'