In a few more words, can you help me understand what 2 partners does that 1 or 3 partners does not.
At its most basic? It adds another partner to relate with. But not so many as 3.
Is it a time thing, where if you have the spare time or energy, then you keep adding partners and if you are too busy with kids or work or looking after an ailing parent, then no more additional lovers for you?
It's going to be personal to the individual. Sometimes it is a time thing. Other times, it is an inclination thing. Or maybe something else. One could even have all the time and energy in the world and still choose not date right now. Mono or poly.
In that case, is (identifying as poly but living monogamously) similar to (identifying as poly and being polysaturated)? In both cases, the thought of new lovers might cross your mind, but the effort required exceeds your time available and so you put the opportunity on the shelf for the time being?
Sometimes, the poly person has their plate full at 0 partners or 1 partner. It depends on what else is going on for them in their life. No different than a monogamous person having their plate full at 0 people or 1 partner depending on what else is going on in their life. Both can notice attractive people in the world. Both can have the thought of a new lover cross their mind. Both can choose not to pursue or develop something there.
I wonder if what you are struggling to understand is more about
- "If my partner were happy with me, and if I were a good partner/spouse/lover/etc., my partner would be so satisfied that (s)he wouldn’t want to get involved with anyone else."
than about trying to understand when one's plate is full/saturated? Is that it?