i appreciate islandscout's post, and that of others who've pointed out the health/ability issues involved in this!
i think the idea of carrying someone over the threshold is rather romantic, but i'm 5'4" and 220 lbs. me and my partners are all pretty fit, but none of us are small and none of us are able-bodied

i don't have a complex about not being carried over the threshold, though. like many traditional romantical-y marriage-y things, i think it's a sweet idea in theory but it would just never work for me/us in reality.
part of the thing that makes me uncomfortable about the idea is that i think it feeds into this ideal of women and femmes being small and cute and dainty...and many of us are anything but (which is something that should be celebrated! imho). i do like when a partner makes me feel small and cute and dainty, and my butch can do that just with his personality and presence, even though he's slightly shorter than me.
but i do have some discomfort around the cultural expectations and issues that arise, especially having felt for much of my life that i am too big, too loud, take up too much space, etc. for what it's worth, i really like my size and my body and personally i have come to terms with the fact that i'll never meet that expectation (and i don't necessarily want to anymore). but i do think it's something that's reinforced constantly, at least in u.s. culture/society.