So, when it comes to humanoid races, this has been a problem for me for quite some time. Sure, mammals (werewolves, gnolls, minotaurs, centaurs) are a no-brainer. I even decided to give tengu something. Though fairly small and don't have to be censored, as they are just two round sacs that produce and store milk, which is regurgitated (read vomited) straight into the beaks of tengu hatchlings by default. Yes, I'm gonna work on that later, but not now.
However, I won't lizard boobs, just no! The reasons are a bit complicated. I don't want to blame it all on Bethesda, but Skyrim certainly didn't help. Also, stop saying that argonians look ugly, it's only because the devs went for the "everything is so bleak and gray I'm surprised players didn't kill themselves after subjecting their eyes to this audio-visual terror with space-time anomalies sprinkled in for five minutes" design. I mean, where are all the toilets and my Dagoth Ur anyway?
But, what are my lizardfolk exactly? Well, there are three subspecies, two of which are fairly humanoid:
Crocodile Folk: The largest, strongest, slightly less-bright. They have very strong jaws and a soft-spot for watermelons and wrestling, with a suitable endomorph body type.
Asian Water Monitor Folk: The most intelligent, quirky, and "balanced" of the three. They actually have venom, even if it's fairly unimpressive. Their build is mesomorph.
Legless Lizardfolk: Also called serpent men, incorrectly, but simply looking at the shape of their heads (plus that they can blink) should tell you that. They love to climb various pillars and hang from piping and branches. Thanks to their size, they can break an adult human's ribs via constriction, just like vipers (see pic related) in Xcom 2. No, they don't have "venom glands". Upper-body is of the ectomorph type.
Okay, back to the task at hand. What visual feature would allow for the quick identification of a lizardfolk's sex? The inspirations for these three have very little sexual dimorphism and I want to stick to the original design principles where possible. I did remove the double trouble for males as they and their partners shouldn't have problems repositioning with their body plan. Other than that, I want to avoid changing stuff.