Get real, in America homes were built with a single bathroom during the big family era, the post war years and the pre-war years, decades and generations of building homes with a single bath, many if not most of us grew up in them, countless millions live with them today.
The luxury of having two bathrooms is a fairly recent situation, most boomers didn’t have 2 when they started life, in fact in 1960 17% of US homes didn’t ANY indoor toilet or bathroom, yet we still never heard of, nor experienced public defecation.
Your description of hand ringing helplessness in an effort to tell us that Americans are, or were having to defecate in public because big sister was putting on her makeup, is silly.
I have lived in those houses and apartments all over the US, they are everywhere, entire neighborhoods of them.
You are spewing nonsense to justify a ridiculous image of British and American dads going out and defecating in the open because their teen son is showering for too long, or because mom is blow drying her hair.
What you are describing is 3rd world immigrants.
I am not trying to convince anybody, or create any image of British or American dads or generalize it as something being done by everybody or happening everywhere. I simply mentioned what I saw during my few visits to London, and tried to explain my opinion since you commented on it. Unfortunately, there is no crystal ball to tell if the turd came from an immigrant or local orifice.