Howrar's being nice about it but here's the way I see it (sightly less nice):

• What someone wants to call their partner/significant other/husband/wife/girlfriend/boyfriend/whatever is up to them and nobody else. Whether or not it's clear is irrelevant. They should share exactly as much or as little information about their lives as they want and use whatever word they wanna use because, simply put, we're randos on the internet and it's none of our business.
• Whether or not these people get married, are married, or even want to get married is a private matter and who they share and/or discuss this with is up to them and nobody else. Furthermore, we are not allowed to have opinions on how their relationship or marriage works. Whether they want to get married after a week, or they wanna casually hang out for 5/10/50/whatever years without getting married, it's their life and as randos on the internet, we don't get and honestly shouldn't even want a say in it. Live and let live, mate :)

Your views on relationships and marriage seem very traditional to me, and that's fine. Asking why people use words like "partner" or "significant other" instead of wife/husband/girlfriend/boyfriend is also fine. But just a heads up, you come off kinda shitty when you say "a joke relationship" and "proves at least one of the people is only wanting a good time" in response to something that's a little different from what you think a relationship should be.