Obviously wasn't the motive to suggest marriage to make him burn with anger when she inevitably cheats on him? Wasn't the whole shtick that the more hatred he has for them, the more powerful it makes the party?
The moment she drops her innocent act I'm no doubt sure she's going to start in the next chapter, she's gonna do that "Obviously to make you mad when I betrayed you! did you think I could ever love you?! HAHAHAHAH"
@Reyzei I think his line of thought was more like "come at me, but before you do, listen to the reason why you shouldn't be that stupid"