So your pecks were on fleek three summers ago and you just so happened to snap a sext-appropriate pic when you were feeling particularly good after a nice shower. That's grand and all, but don't send that washed photo if your pecks are now more on par with Lil Terrio's than Channing Tatum's. That's called false sexting, and it's illegal (or should be).
The thing about sexting is, it should happen in real time, meaning old photos originally saved on your iPhone 4s don't work. The most successful sexts are those that reference and take advantage of objects, body parts, and clothing you have in front of you in that moment. Just like if you were interacting IRL right then.