I use a suction machine. You can also use the same device new mothers use to express their milk. As long as the nipple is being tugged and pulled often, daily, the nipple will grow. I have also used nipple shields that grip the nipple at the ba<x>se. It helps the nipple stay hard and protruding for longer. That is how I got my nipples to stand out in my profile picture. They are the longest after someone sucks them for a while.
From experience alot of sucking and twiddling seems to do the trick,you will soon be able to hang your coat on them hahaha
stretch em all day e'reday
surgically implant a steel plate in them.
ask your bf he will glad to help