Here are some of the responses, all of which reminded me just how painfully oblivious I can be:
1. "The two of them consistently being the last ones left at the group hangout, especially if one of them is hosting, is a huge flag they're involved."
2. "They almost try too hard to hide it. Like, if they go to an arcade with their co-workers, they’ll play different games but right beside each other instead of just playing together. Or they’ll flirt with total strangers at the bar area. Or they'll freak out if people think they’re flirting, and other stuff like that."
3. "The little conversational clues. Like when two people glance knowingly at each other frequently, or have friendly little side whispers because they have their own thing going on apart from the group. And they hover near each other to be physically close. All those little examples of intimacy that are only between them.
4. "I saw Venmo payments for grocery items, even toilet paper, which I thought was too personal of an item to be sharing expenses with for a non-roommate."
5. "When your significant other brings someone up way too much in the beginning, then mysteriously stops talking about them at all, even when the situation potentially calls for it."
6. "I’ve caught people because they didn’t follow one another on social media to try to avoid suspicion, but they both posted that they were at the same place and similar photos, and despite not posting about one another, it was obvious. They didn’t know what the other was posting because they didn’t follow one another, lmfao, which ultimately lead to the downfall of their discretion."
7. "This is from my personal experience — I was hooking up with a coworker, and she'd bring her dog into the office. Her dog started sitting under my desk every day, and we were exposed."
8. "They stop saying thank you to each other. Got caught out myself with that."
9. "The thing that has gotten myself and others busted is changing how we interact with each other at the office. In the lead up to dating a co-worker, there is usually flirty behavior between the two people — it's not inappropriate, but it has a certain energy. When you actually start dating a coworker and the two of you want to keep it quiet, I have noticed some people (myself included) will try to out-clever themselves and tone down their flirtatious behavior at work. Well, that's a change, and changes in behavior make something more noticeable.
10. "They make sure to not leave a place together, but one of them will always linger around long enough to know when the other is leaving. And they look at each other when something funny or bad happens."
11. "Staring. I was secretly seeing a guy in school, and as far as everyone else was concerned, we couldn’t stand each other. One day after class, this girl I barely knew pulled me aside and whispered, 'I don’t know what’s going on between you two, but you need to stop staring, or everyone else is going to know.'
12. "A bunch of us used to hang out on a TeamSpeak server to play games. One day, we were chatting when the server admin just blurted out, 'So two of you have the same IP address today. You screwing?'"
13. "Sometimes, you can tell by the way they casually (appropriately) touch each other in public. Certain things are awkward until you cross that line."
14. "If someone says something not so loudly but one person picks up on it and has a noticeable reaction, even when the rest of the group doesn't, that's a huge giveaway. It's an even bigger tell if they try to cover or restrain that emotion."
15. "It's definitely the awkward avoidance of one another for no reason."
16. "They start using each other’s speech mannerisms. Like, in my case, one of them always replied to something I said to them with, 'Is that right?' And then I heard my wife saying it all the time after I got back from a week-long work trip."
17. "When you ask someone how the other is doing or what they’re saying, and the response back is something short or dismissive like 'I don't know' to cut the conversation off."
18. "A giveaway is how friendly one person's kids, if they have any, are to the other person. I had this happen to me with a co-worker when we were trying to just play it off that we were friends. Her kid would smile at me as he said my name."
19. "Carpooling even when it's not convenient to do so because they don't live all that close to each other."
20. "Their orbits are smaller around each other. Without meaning to, they will change their personal space requirements with the other. They'll think they're normal distance away, but won't be. Also, they'll move around each other too easily, particularly in small spaces, without the awkward missteps the rest of us would usually make."
21. "They get awkward if you come up to them when they are together. I just want coffee, and you’re standing in front of the machine, and I didn’t think anything was going on until you got all awkward. You’re allowed to be friends with someone and just stand somewhere and talk."
22. "If your partner goes over the top with talking about how unattractive, uninteresting, cringe, weird, etc. the other person is, they're probably hooking up."
23. "I'm suspecting two of my co-workers are boinking — one of them continues hanging out with the other even if one of them is already clocked out. There's lots of standing around and talking when one of them can walk around anywhere, yet only spends time at the front desk, where the other coworker is. And one of them mentioned that they smoked together, which is a big sign in my opinion.
"It's just a general 'this person matters the most' type of attitude."
24. "Going on way too many long coffee or lunch breaks, or bathroom breaks suspiciously within a few minutes of each other. And frequently taking the stairs together."
25. "They start watching the same shows and engage in new interests that are out of character and seem odd to you.
26. "Breaking eye contact a little too quickly. I was once at a barbecue with dozens of people. A young, ridiculously beautiful, and recently expecting married couple showed up. They brought their short, squat, funny-man roommate with them. At some point, funny-man and pregnant wife are on opposite sides of the kitchen — I caught a glance between them that was no more than a blink of an eye. But it was the only interaction they had all night. In that instant, I have never been more sure two people were intimate.
"I told my girlfriend, 'Those two are smashing,' and she told me to stop being a creep. Six months later, sure enough, everyone found out the roommate and wife were having an affair, and she was carrying his child."