They slouched tiredly, sitting across from each other. Two lackluster diamond statues that did not shimmer, shine, or otherwise attempt to sparkle. The static night air coated them like slime, and an ear shattering silence lamely clanked back and forth between them like an errant ping pong ball. Any attempt at conversation was soon suspended by prolonged hesitance. Their fingers twitched. Their noses itched. And as such, the night slogged on.
They were on date.
Or they were supposed to be. As it is apparent, it wasn't turning out.  
For the sake of storytelling, let's call the one sitting on the right of their morose, painfully silent table Sally. And the one the left--John.
Sally and John were both, respectively, in unutterable agony, as caused by the sheer discomfort fermenting in air they both attempted to breathe. Their lips were affixed to their teeth, and their joints creaked with their every movement. Any and all eye-contact anxiously dodged. They were hopeless.
Sally (with desperation) opened her mouth, fruitlessly, and spent the next thirty seconds attempting to force her larynx into submission. Into function. She did not succeed. She seethed with frustration.
John, on the other hand, was struggling to wick sweat from his drenched brow. He was trying to be casual about it. He was failing--there was too much sweat. He was hot.
Whenever he was nervous, he got hot. There was nothing for it.
At some point in time, their waiter tramped up to them, asking for their order. Confronted with this question, John and Sally mutually discovered that speaking to the waiter--a third party member-- was rather painless. They ordered with ease. Conversation was piquant and comfortable.
Yet, when the waiter retreated, their table regressed back into the gutter. They couldn’t seem to speak to each other. The date atmosphere was too much. They couldn’t, as you say, act natural.
Basically--the jist of the situation is--they were your average, slightly pathetic, thirty-something, single somebodies. Who spectacularly didn’t fit. But then, the word fit doesn’t properly describe the situation, does it? It was less that the two were just incompatible puzzle pieces, and more that each had their chin tucked into their collarbone for fear of the other’s claws at their neck. 
At no point during the night had vulnerability been bared, exposed, or given freely. 
So they wallowed. And sat. And wallowed some more.
And it was okay. Well, alright, at the moment it wasn’t okay, they were both currently engulfed in mentally scarring levels of awkwardness. But later, we they finally extracted themselves from their seats, and went home, ripped their shoes and shirts off, and thanked God that it was over, it was okay. They were okay.
Neither of them were quite ready for a relationship. Not yet. Not now. Maybe later. Maybe never.
For now, they were okay.
Single.