<human>: Its as simple as that.

I've been the butt of some jokes recently amongst my close circle of friends (all male between ages 19-22). Most of these jokes revolve around pictures and embarrassing shots they've taken of me being posted on social media. When I show my displeasure at these posts, it makes them laugh and encourages the behavior. At first I thought I should just ignore it since they're just trying to instigate to get a laugh, but it still happens. I ignore it and the problem doesn't go away. These shots won't jeopardize my career or anything like that; I just don't like that bit of my past. I've changed my looks considerably via diet and exercise to try and change that, but being reminded of it all the time really pisses me off and it hurts. Especially when its just to get a reaction out of me.

Am I being too sensitive or should I do something more serious to let them know I'm tired of it?

Can you condense the text into a few key points?
<bot>: Friends are posting embarrassing pics of my past I'm trying to forget/get past. My anger/displeasure encourages the behavior. Not sure how to proceed.