Sex =/= Penetration
There is more to s-x than penetration. Due to the overwhelming cis heteronormative concept of s-xual pleasure, other forms are taboo, unexplored, not s-x, or "reserved" for certain people (i.e., LGBTQ+, BDSM community, etc.) The presence of a p-nis is not the end-all, be-all of pleasure, and this belief affects people's access to various types of pleasure, barrier options, and STI transmission conversations. It also affects people's knowledge of how to please themselves. Often in polyamory, just like monogamy, relationships are "validated" by penetration or the presence of p-nis (if attached to a cis man). If no cis men are present, those relationships may be devalued or fetishized by the "male" gaze.
When does it start?
One way to start unpacking and reclaiming pleasure is to note when pleasure begins for you. The start of pleasure can be the new start of s-x for you. S-x does not have to be started by penetration from a p-nis. Maybe it's when your partner(s) stimulate your erogenous parts or when they kiss you. For some, the experience of pleasure is simply a change of atmosphere to something more intimate like candles or a warm bath. For some, a touch is all it takes to trigger pleasurable stimulation. For others, penetration is not even in their plan for pleasure. If you cannot think of a time where pleasure had begun before penetration or the presence of a p-nis, think about the things you would like to happen to create pleasure for yourself. What do you imagine that looks like for you? S-x should not be a single act - it should be a general experience that has a beginning and end with or without the initiation of penetration from p-nis.
Foreplay is sex.
Foreplay is s-x. The acts that happen during foreplay - kissing, fondling, petting, use of toys, or-l, etc. -is s-x for some people. Redefining not only when we see s-xual pleasure initiated, but WHAT we see as s-xual pleasure will enforce its validity. Foreplay is often seen as a precursor to s-x, or something done to "warm-up" the body for penetration. Sometimes it is rushed or used as a transaction for access. Call foreplay what it is, s-x. Not only call it what it is, demand the acts that happen to be given the same care and attention as one would be it an act of penetration by a p-nis. This means not feeling rushed or only doing these acts as a starter. Also, not treating foreplay is not transactional.
Why should we shift focus?
It's ableist, transphobic, cis-focused, queerphobic, heteronormative, and p-niscentric focus towards s-x. This thought process decreases access to pleasure by those affected. So much is being lost in experiencing your partner(s) when s-x is limited in this manner. s-x toys aren't just for people with vulvas, and creating intimate moments isn't just for Valentine's Day. As the saying goes, there are more ways than one to skin a cat.