A situationship falls under the latter camp.
Are you thinking of the 2011 movie starring Mila Kunis and Justin Timberlake titled “Friends with Benefits”?
You are pretty close but there’s a difference.

A situationship doesn’t really have the clarity of a “sex with no strings attached” arrangement.
And there’s also a level of emotional attachment.
Situationships arise for a number of reasons, fear of commitment and having different goals being two of them.

Timing can be another reason too.
Do you fear you might be stuck in a similar situation?
There are usually signsto tell if you’re in a situationship.Here are some of them.

Another sign, according to psychologist and relationship coachDr.
Contrary to what you might think, there are ways to get out of this.
Do you want to be in a relationship that isn’t defined?
Are you okay with them dating other people?
If the answer is “no,” then you’re better off making a change.
You’re going to need a bit of self-love and courage to ask the person directly what they want.
If they’re unsure, maybe you could ask them to take some time alone and figure it out.
Try and keep your distance during this time apart.
If they’re agreeable to meet you where your needs are, then great.
If they decide to cut and run, you’re better off without them.