If we're talking about real life though, anything but an explicitly stated "yes" is a no. I personally think that what happened in this manga constitutes non-con. In situations like this, especially when the aggressor is someone you know and trust (which is more often the case than not when it comes to sexual assault), it's not always easy to just fight back. It's not that simple. If Person A comes on to Person B, the burden of making sure the situation is consensual rests with A, not B. There was a time not long ago (and it may still be going on) when people's lives were ruined because they were assaulted but nobody believed them, because they didn't conduct themselves in the "right" way. But that's an unreasonable expectation, because when someone's being violated by a person they trust, they're under a great deal of emotional/psychological stress. You wouldn't say that someone willingly gave up their purse to a thief just because they froze up from fear in the moment.
I get it, this is fiction, we shouldn't take it seriously, if the uke doesn't consider himself a victim then neither should we, there might be some Japanese cultural conventions that I as a Westerner don't recognize, yada yada. But please understand that the sort of logic you're using here is problematic and even dangerous if applied to a (Western) real-world context.
I completely agree I mean I would never apply this to real life considering... well... I just could not imagine there could be a person like this character in existence. He's too odd to be real and not have mental issues. That's the beauty of manga. Another thing that wouldn't happen in real life is the soooo common to see tsundere trope. When you factor that into yaoi rape scenes it's just... dear god let's not even go there.
Ok I have seen plenty or rape yaoi and lemme tell you, this is not one of them. The uke clearly never once tried to push him away (he freaked out when the sex got intense but I'd assume most would if you tried to stick a needle in their dick) from the very beginning he was all "oh my friend is having sex with me and stuck something in my ass, that's not normal right? Help me let him down gently" like no. Just no. That is def not rape. If someone raped me i would never want to see them again and woukd fight back with everything ive got. Dubious consent perhaps but unless he had some bone disease so as not able to fight back or mental issues which cause him to not understand his sitution, that was not rape.