I totally agree with you. it was just a playful interjection
unfortunately, as eyg"s link points out, it is near impossible to sex them correctly if they haven't truly paired up. I have a male and female, but the female is the one with the longer streamers. You only really really know which is which when they get ready to spawn. Then the female's belly really plumps up. The female has also been slightly bigger in the pairs i've had. The best you can do is check their behavior to see if you have a pair. They will flare up at each other, that's normal, but do they hang out together? Do they pick some area clean occasionally? Do they chase off other fish more often then each other? if so, you might have a mating pair.