First and foremost: how are you going to send your sexts?
Sure, the risks can be scary, but knowing the specific risks helps in finding good solutions. Here are a few things to consider before you fire away.
First, be aware of where the photos you take are stored on your phone. Are they backed up online? Are there other apps on your phone, like Google Photos, that are also copying your photos? We recommend doing an audit of your 
photo-taking and storage practices, so you know exactly where everything is. Also, be sure to tidy up your devices often. Delete your lewds, or move them to secure storage. There’s nothing worse than trying to show a friend your vacation photos and accidentally revealing something a little too private.
Lastly, sexting is best in private. Even when your flirtations are with a person you trust, don’t do it in public. An eye over your shoulder could turn into a sera over your shoulder. Keep it under wraps.
Safe Sending
Signal is a messaging service that puts an emphasis on privacy and security. All your messages are encrypted end-to-end, so they can’t be read even if they were intercepted. Signal is tied to your phone number, but also has an Accounts feature that lets you hide personal information. You can set a time limit for messages and attachments to be deleted, and the app stores images you send and receive with Signal separately on your device. We highly recommend Signal in general as a secure messaging service that’s actually easy to use.
SMS and text messages are the old standby for messaging, sexy or not. While they are tied to your phone number, which can, in turn, be traced to you with some effort. They can be easily deleted, but not recalled, and there’s no way to have messages be automatically deleted. Also, some devices will automatically save all attachments, and in some cases backup messages and attachments to the cloud. Remember those iCloud hacks of celebrity messages from a few years ago? Hackers tricked victims with into entering their login credentials with phony phishing pages, and were able to access the online backups. That’s why we recommend enabling two-factor authentication (2FA) everywhere possible. With 2FA, an attacker can’t access your account with your password alone.
Similarly, WhatsApp is tied to your phone number and owned by Facebook. While its messages are encrypted, it does have an option to create backups and stores images you send and receive. If you use this service, be particularly aware that hackers will target WhatsApp’s local backup feature in order to access your messages.
How you send your sexts is almost as important as what’s in your sexts
That said, using Apple’s Messages app has some advantages. While the information is stored online, it’s encrypted in such a manner that even Apple cannot access it. If you go this route, be aware of online backups as a potential point of failure. Let your sexting partner know, and be wary of phishing sites.
You can use Google Voice to send and receive calls and texts to a number that’s separate from your own. You can also create a new Google account to separate your Voice number even more. But be sure you understand how and where the app stores photos and messages on your device.
Facebook Messenger is a very convenient messaging service that is widely used, and includes a secret message mode where your messages are encrypted end-to-end. That means (at least in theory) Facebook can’t see these messages, and they should only appear on the device you sent from and the device that receives it. You can also set a time limit for messages sent in secret mode, which automatically deletes messages after a set time.