So, there is a lot to be said here. I think the first thing important is this:
Basically, there shouldn't be sexual roleplay in the game. I get that it seems like it is ok, but we also have no actual way to prevent minors from the game. With harassment laws, and child protection, and all of this stuff, it is best to just avoid it. The last thing I think any player here wants to do is create a scarring situation for a young person, simply out of ignorance. It could be as simple as referencing personal preferences (not gender, but traits), that could cause body shame in a person.
As for the actual way it operates, there is definitely a leaning towards male and female lizards IG, as opposed to asexual. I think most current roleplay leans towards them not carrying eggs, but laying eggs.
As for romantic encounters in game, I would recommend that if your character gets into situations like that, to take it to a private location, and log out.