the commonly used definition/understanding of what a situationship is, as far as i see, "Person A and Person B are in an undefined relationship with no explicit commitment, typically with a sexual component to the relationship, and may or may not include activities that could be called dates." and this usually comes with an addendum of "Person A wants to be in a defined romantic(+sexual) relationship but Person B does not want to "commit"."
the part where amatonormativity really shows itself is when the discourse becomes "all undefined relationships/situationships are inherently unhealthy", because this is based off the assumptions that a) one party in the situationship will always have entered with the intention of it becoming a romantic relationship, b) that everyone must eventually want to commit to a long term romantic relationship, and c) wanting a non-committed/undefined relationship such as a situationship is somehow bad.
There's honestly so much I could say on the topic but here are my two main points:
- People seem to miss that the concept of a situationship (taking it as an undefined relationship) is not what is wrong with most peoples experiences, what is wrong was the lack of communication and the fact that the two parties were not on the same wavelength (Which of course, it does hurt when someone does not return your feelings, but that does not mean they are in the wrong for not reciprocating.)
- criticism of situationships often comes with sex-negative sentiments that it is bad to have relationships primarily centred around sex, or that it is toxic/immoral/etc. to only want a sexual relationship with someone.
oh, and also: Since we live in an amatonormative society, where a long-term romantic relationship with a person (that would become marriage) is seen as normal and what everyone should be doing, This is why the discussion around situationships has gone this way. If unlabeled/undefined relationships were destigmatised I don't think that "situationship bad" would be such a common feeling.
I think that genuinely the discourse around situationships is very heavily baked in amatonormativity. Like, having been in aromantic spaces for a fair few years now, I know a fair bit about amatonormativity, relationship anarchy, etc, and when I first heard the definition of a situationship, my first thought was "oh cool a new way for people to describe a relationship". And then I realised that the general tone surrounding it wasn't positive.
And people definitely get arophobic, because whichever party who does not want that commitment to a romantic relationship/does not return romantic feelings, is always demonised for not wanting that. Furthermore with the sex-negative aspect to a lot of it (i.e. "wanting an only sexual relationship is cold/unfeeling/immoral/toxic") that compounds with stereotypes about aroallo people.
(I am also aware that describing a relationship as a situationship does make it a defined relationship and puts a label on it. It's a contradiction in the language used that I couldn't quite figure out how to get around in this post, and most definitions of situationships I found were very similar to definitions of undefined and unlabeled relationships, with the difference being the label.)
I also think that although the way the conversation has gone is very influenced by amatonormativity, another major factor is a lack of communication. Which brings in the common adage of "communicate or break up".