Is this the most safer version of sexting?

So I wanted to send a nude to a guy and I was wondering about the possibility of getting a screenshot of the picture. I’m not sure if he can or not or if the iPhone will even allow it. I also wanted to see if the iPhone will alert me if they take a screenshot. <br><br>So I decided to take a picture of a tree outside for sure this out. So I sent him the picture and the iPhone did alert me that he took a screenshot. I’m wondering if this is a safer way to sext? Or is there an app or service that’s more secure?