"Secure" sexting

My husband loves when we talk "dirty" to build up the excitement when he's gone at work or on a trip. I would love to send him nudes-- makes me feel so empowered when he gets all excited about my body and I forget about all my body insecurities. But Snapchat saves everything on a server... texting can take several steps to delete... my husband is super protective of my modesty (I save me for him and him for me!) what do you use to keep your private messages PRIVATE between you and your special person?!?