Just to clarify before I get into my question. I'm a 17/yo guy.

Some background; I've sexted girls before but it was just kind of happened. I have a few female friends that I've gotten to know fairly well and a few newer friends. The girls fall into two categories. 1)Newer friends that I'm still getting to know but have a reputation of somewhat slutty 2) Friends I've had for a while and want to advance things with.

How do I bring up/suggest sexting and or trading pics without coming across as a huge perv? Once I get there how do I keep it going so Its not just a one-off thing?