Relate to that on a few levels.
People communicate through their perception of actions, and not necessarily what is explicitly being said. People often kind of lead with their egos. I
There's no doubt that it's not as easy to actually like someone, sleep with them, spend time together and then NOT go as far as formalized relationship. a lot is just social pressure and reward. Someone will mostly be rewarded for being in a relationship. A woman will mostly be looked as lesser for what I described above. "situationship" or what about just two people who fukking like each other lol
As someone who extends a lot of invites, it takes confidence to do that, and it's always an ego hit on SOME level when you are rejected. But, the key is to not look at it as a rejection of yourself. Not everyone can do that. I feel you, sometimes it's not the person, it's the invite. I'm like that doesn't sound fun to me. Down to hang but not rock climb or whatever. but, when you do that, she feels you are breaking an unspoken agreement, that you owe me.
what roles do (boyfriend/girlfriend) is establish formalities and a framework for how to deal with situations, when you blur the lines, it's harder. it requires really good communication and expectation setting. mutual consideration, respect, here's one I learned: unconditional positive regard. which is basically always viewing the person in the most positive way, even if they let you down. Doesn't mean no boundaries, it's just a framework to view people. Mostly what you experience is people are highly conditional, and have poor conflict resolution skills.