Duath Velde

Okay, now, i've tried to find a singular statement on what ageplay exactly is and how it is restricted in Second Life. From what I understand, no sexual acts are allowed, period, with child characters. However, my question is how this effects avatars that are far older, but still appear young. For example, Elves, Certain Anthromorphs, Dwarfism, etc. where the character may appear to be under 18, but is actually well over let's say 60 for this example. What are the rules on -this-? I ask because I do not want to be in proximity of something considered 'illegal' by Linden, even if it is legal in the USA.