ML literally said he's been doing it since the MC presented as an omega which means he was aware he was scenting the MC and chose to keep doing it instead of stop and either ask for the MCs opinion on him senting to "protect him from other alphas" or at least ask for consent to do it., re-read chapter 4 they have a conversation about it and its apparent that the ML knew what he was doing and juat kept doing it anyway. Not only does the MC not want to be sented now(or when they were kids) but the ML still does it and then goes on to assault the MC cuz suppressants dont work since the ML has been forcing scenting on him.
He quite literally presented when they were kids so when you're a kid you cannot control that and if you do you kind of like don't realize that it's bad to do it without asking someone first he did it with good intentions when he was a kid when he got older he should have stopped yes but I think you're reading the whole situation a bit wrong...

Now, now, ain't the bot just insecure he ain't an alpha? I kinda feel bad for the top now