I did a bit of digging. Apparently, it first appeared in Maison Ikokku (1980~1987) by Takahashi Rumiko (Ranma 1/2, Inuyasha). In the story, it wasn't spoken, and was just one of the lines the male protagonist thought of when coming up with lines for proposal in his head.“I want to have this every day”
Is such a simple innocuous comment, it’s quite a stretch to think that means I want to marry you. Is it a translation thing? In Japanese is there a double meaning?
It’s just such a common trope and I don’t get it.