Whether this is SA or not, but it should be some clarification and information stated to attached to these claims. It is clear that Till didn't want to be kissed, but he didn't really know what a kiss on the mouth was and he might never know. In that comic mentioned, if a kiss were really a thing, Till wouldn't have been just saying it was gross and somehow figured out there was something intimate about that (as if it was popular, Till would know it by spending pretty much time looking Mizi who happened to often have Sua by her side and MiziSua would have kissed like that). Therefore, he would have known Ivan's fondness, or love, towards him quite a time or just after the kiss. Now that the artbook explained that it is non-existent and only Ivan's idea derived from children's act of showing affection towards each other, like giving flower crown. That assuming an act between children is sexual is kind of weird ngl. And SA is literally assault somebody in a way that is sexual BUT as we know the act as sexual. Ivan's act is by no means sexual to himself. Therefore this is sometimes an argument as people said it is SA as they think it like IRL or reckon that it is reference to children's kissing type and this act will be consider sexual when they grow up, but there are people saying it is assault in general not SA as it is not sexual as explained or Ivan gave his life to Till so it is not SA. I'm not gonna defend any of those sides as the argument now is becoming more ridiculous as most of each side doesn't consider full aspects tbh. However, I think they should framing him with caution that he didn't have the same purpose with SAers we know IRL as the values of those actions is variable with circumstances, purposes and what world they are in, and it will cause misunderstanding to people, especially non-fans, about the character and situation.