The code you have works fine in fiddle. Is your button being dynamically rendered through AJAX after the initial page load?
Use
$(document).on("click", ".remove_weight_button", function(){
instead of
$(".remove_weight_button").click(function(){
The code you have works fine in fiddle. Is your button being dynamically rendered through AJAX after the initial page load?
Use
$(document).on("click", ".remove_weight_button", function(){
instead of
$(".remove_weight_button").click(function(){