I have a few years ago, yes we were both underaged (so shhhh), yes she sent one too and no neither of us have them any more. We're very good friends now (we dated then) and deleted the pictures together.
Would I still do it with my current girlfriend? I would consider it honestly if she asked for one, but I don't know. She's not a fan of sending nudes or anything herself (she's scarily good at sending images that are erotic as fuck but not explicit though).
What I don't like about the legal issues around nude images, is that in my country (and many others) you can do anything you want physically with a person at the age of sixteen, but if you send your lover a naked picture you can be imprisoned for the distribution of child pornography. That seems ridiculous to me, if you're old enough to get naked and have sex - acknowledging the risks according to the law - then really the same should apply to displaying your body. It's not exactly a good decision, I don't encourage the practice, but logic people. Logic.
So yeah, send them/receive them at your leisure just make sure you know the risks. Also the law is stupid and illogical.