Must Be 18:

There are no sexting services which will connect you to a partner for free. Every phone number we found charged either for a bundle of texts at some fixed cost, or on a per text basis.

You may wish, however, to try one of the free social networking websites that allow you to search, or post "personals," for others interested in similar activities.

We found one on LiveJournal called TextMe which lets you post your own "personal ad" looking for someone, or read posts from others searching for sexting partners (Note: not everyone there is looking for sexting, some just want to text chat with someone, so be sure to read the entire personal ad before texting them)

Media organizations have been suggesting that Snapchat, the instant messenger that allows one to send photos from their smartphone that will self-destruct within 10 seconds after viewing it, is being used for sexting; Evan Spiegel, the CEO and cofounder of Snapchat claimed to Business Insider that people are not using the app that way.