I'm sorry, but... when I see extreme cases of such a couple, I always feel very awkward and puzzled. Because... jesus, honestly, I have no idea, how can they make sex with such a different sizes of their bodies! I mean, of course, I've seen a couple of "Exxxtra Small" porn videos with skinny women of small stature and pumped up guys of big stature, but they are still nothing unusual compared to cartoonish couples...
For example, it is exactly what I've thought, when I've firstly seen parents of Marinette (from Miraculous ladybug cartoon):
I know, I'm too naughty, I shouldn't think about such a things watching kids cartoons... but I can't.