I live with my husband and my boyfriend (both straight) in a one-bedroom house. We share one king-size bed - I get the middle. When Dude's girlfriend stays over we sleep four to the bed (either MFMF or MFFM - MrS's request is that he gets an end).
When no-one is using the bed for sleep - any combination can use it for sex. If someone is using the bed for sleep then the sex-having people need to find another location. (We don't have kids, so this isn't an issue.)
Outside of the bedroom/bathrooms - we each have areas of the house that are "ours" - to retreat to, to decorate, to determine its uses, etc. The eventual plan is to build an addition with another bedroom and space for "private entertaining" without encroaching on the "common spaces"...but that is probably a few years off.
Both of the boys are WAY more social than I am...and would like to have "outside" people over on a more regular basis than I am comfortable with (my house is my "cave" - I have a short list of people that I am ok with having in my "cave" - the addition would address this.).
Me: poly bi female, in an "open-but-not-looking" Vee-plus with -
MrS: hetero polyflexible male, live-in husband (23+ yrs)
Dude: hetero poly male, live-in boyfriend (4+ yrs) and MrS's best friend
Lotus: poly bi married female, "it's complicated" relationships with Dude/JaneQ/MrS (1+ years)
+ "others" = FBs, FWBs, lover-friends, platonic G/BFs, boytoys, etc.
My poly blogs here:
The Journey of JaneQSmythe
The Notebook of JaneQSmythe