
Quoting
Taxing Matters
First, your assumption that the others were in the U.S. simply because they spoke with you in English might be wrong. While the U.S. is the nation with the largest number of native English speakers (i.e. English is their first language), it is of course not the only one. They might have been in the U.K., Canada, Australia, New Zealand, or a number of other island nations where English is the primary language. Then there is the fact that English is a widely learned second language, so there are significant numbers of people who speak English in a lot of countries around the world. My point here is that since you don’t know in what country these people were located you don’t know what nation’s laws might apply here.
If you are correct and they are in the U.S. then a similar problem is presented. The U.S. has 50 states, the District of Columbia (DC), and several territories and possessions, each with their own criminal laws. In the U.S., most criminal law is at that level, not the national level.
With that said, if this was in the U.S., your biggest problem here would likely be if you are also under age 18. If you are under age 18, then your exhibition of your genitals would amount to child pornography, the distribution of which is illegal in the U.S. under federal law and the law of at least some states. That said, for this one incident I think it unlikely you’d be extradited to the U.S. for prosecution. You were not, after all, exploiting any minor other than yourself.
If you are over 18 but they were under age, then you might still face some risk of distribution of pornography to minors, but such charges are generally not that serious and not something any jurisdiction in the U.S. would put much time into investigating, let alone extraditing you from Spain to prosecute.
Bottom line is that if they were in the U.S. I think it is unlikely anything will come of this. But I suggest that in the future you not get involved with this sort of thing with anonymous people on the internet since it is very difficult to verify ages and locations of people on web cams. There are some countries where what you did would be a crime even if those other people were adults, after all.