In fact, there's a whole group of them here, all connected to one restaurant in some way, and all in suits, with pocket squares and brogues. They swoop about the stall taking turns to chat up the women in its vicinity, who are mainly glamorous PRs a third their age. Despite wedding rings glimmering on most of their left hands, their eyes go up and down our dresses like lifts.
"What just happened?" Ed asks once we escape. I shrug. This isn't exactly a one-off. I'm 28 and I get chatted-up by men almost double my age all the time, as do my friends — and there are statistics to prove it.
The online dating site OkCupid found that while women looked for partners roughly the same age, men — regardless of how old they were — preferred 20 to 22-year-old girls. This makes me cringe, but it doesn't surprise me, especially when it comes to online dating.
Older men have always chased younger women, with some studies even arguing it's an evolutionary imperative. Now websites and apps such as Tinder have exacerbated it by making the approach all the easier.
In tandem, the explosion of online dating seems to have given men of a certain age the nerve to approach women decades younger offline as well.
But the virtual world is the midlife man's favoured hunting ground. If you're 50-odd and want to chat up a twenty-something, you risk them laughing in your face if you walk up to them in a bar. Online, you don't even know when you've been rejected.
After setting your age preferences to anything between 18 and 55-plus, you simply scroll through images of potential "matches" on your phone screen, swiping right for "yes, please", and left for "not in a million years".
In short, you can be as ambitious (or deluded) as you choose, without any risk of having a drink thrown over you. Dating apps are so user-friendly and people "swipe" in such volume that they only really notice the matches, not the lack of them.
So a 49-year-old promoter named Earl, who's undone one too many buttons on his shirt, and has a chunky gold necklace nestling in the chest hair below his overly fake-tanned face, never needs to know I've saved his picture and sent it to a friend accompanied by an emoji of a sick face.
Likewise, a 56-year-old who looks like Eric Pickles and says he can "talk all night after a bottle of Chablis or 17", doesn't realise his chat-up line is now used across London by my friends. "I bet he could talk all night after a bottle of Chablis or 17," we say, if we see someone particularly dreadful-looking in the pub.
Now, it's something to laugh at. But when I was using Tinder a couple of years ago, it shocked me how many men in their 50s and 60s I was "matched" to (not realising a friend had spread my age preference on the app to 55+ for a joke).
After the shock, I was horrified. I know a few people who have found their fiances on Tinder, but it still has a reputation for being a "hook-up" app. I wondered whether these men actually thought I'd have sex with them. Did they think they were so irresistible I'd overlook the fact they were balder than a sphynx cat and would probably need to spend each afternoon napping?
My friends and I sat incredulously flicking through their profiles, alternately crinkling our faces into grimaces or collapsing into hysterical laughter.
Frank, 49, boasts on his profile: "Porsche, yacht, Harley Davidson, horse, champagne." Is this some kind of game show?
But how I wish they could hold on to the dignity of their years with a little more success. Take the men who lie about their age — and there are plenty of them. Some lop off a decade to cheat the dating app's filter and pursue women who've set their age limits years lower, before confessing in the blurb with a sheepish '48, not 38'.
But for those who don't confess, well, you can tell the second they start to message you. Simply put, old men use tech in a completely different way to millennials like me, who have been glued to phones since we were 12.
They use emojis thinking it makes them look "down with the kids", but always pick the suggestive ones. Conversations are so full of winking faces, you begin to you wonder if they've got a twitch in real life.
They also take ages to type, so by the time you've waited for a message back, you're bored and have moved on.
And, yes, selfies are awful, but badly taken selfies are even worse and older men have no idea how to use a phone's camera, it seems. Angling it from beneath the chin, they point it straight up their (not always well-kept) nostrils and, because they're holding it far too close, their pallid faces fill your entire screen.
Others decapitate themselves when uploading topless full-lengths, offering only pale one-packs from the neck down. Past 50, some men advertise that they have their "own teeth and hair" Their eyesight, if they think these are good photos, must be shot.
On top of that, many also post pictures showing millennial daughters who look a bit like you, which is just wrong.
My friends have had similar experiences. Billie, a university friend who's now 27, sends me a picture of a 56-year-old she's matched with named Tim, whose profile says he's bought an "old house" in Bordeaux and would love someone to help him "do it up".
"Does he mean he's looking for a decorator?" she writes. "Although I do like Bordeaux," she adds, more seriously: "Shame we don't know what he looks like. Must be bad."
We don't know what he looks like because his profile picture is a dog sitting on a lawnmower.
Materialistic boasts (or offers of French property) are so constant it's embarrassing. The profile of 59-year-old Jerry shows only his watch face, presumably because he wants women to see he's got a £4,000 Panerai Luminor watch.
Similarly, floppy haired, 49-year-old Frank, whose suavely clipped beard is melting into silver, just lists his possessions: "Porsche, yacht, Harley-Davidson, horse, champagne," he writes. Do you win them if you sign up to him? Am I on some sort of game show?
It amounts to a tacit confession from the older man that he's got less to offer than you have: you have youth and looks; he has a face craggier than Snowdonia, but you can look at it from the passenger seat of his Porsche.
That's way north of gold-digging in my eyes, and while some women are happy to trade their bodies for material goods, I'd be surprised if one half of the transaction doesn't get very boring, very fast.
There's a general impression among my friends (a lot of whom see 40 as the cut-off point for dating) that men get more deluded about their pulling power with age. My friend Charlie agrees that apps have made it "a thousand times easier for old blokes. When you're 26 and someone of 50 walks up to you, you think, how arrogant are you? They're always punching."
"Punching" above their weight is the default strategy of men online. They seem to approach dating in the same way they do a new job or promotion. But instead of going for a better position and bigger wage, they're looking for younger, more attractive women.