You can send "sexy" pictures, in your bikini or lingerie as long as the material is not transparent or that there are no private parts showing.
https://www.inmateaid.com/ask-the-inmate/to-what-extent-of-pictures-can-i-send-my-inmate-am-i-aloud-to-send-pictures-in-my-bra-and-underwear-or-in-my-bikini#answer
Accepted Answer Date Created: August 06,2015