Don't. It will end up somewhere on the internet and what ever you post on the internet is accessable forever. Ever version of your facebook that ever existed, every photo on your flickr, despite if you've deleted it is recoverable. Just remember that if you decide to go through with it.
Depends if you have messenger, make sure he has a webcam too so you can see if a third party will see it too.
But you install the webcam, click view my webcam, invite him to it, then you lift your shirt and show him your 'goodies'.