Thanks for all your comments, I will try to improve my story telling in time.
Here is the third part. Once again I will appreciate any suggestions on how to move the story forward.

CHAPTER 3: NIPPLES
Maria felt the coldness of the steel blade between her breasts, but something strange was happening in her… her body reacted with lust instead of fear. The vibrator in her pussy was keeping her on the edge of an orgasm and she was moaning from behind the tape.
The man was surprised to see Maria’s that nipples where rock hard, those pink and sensitive nipples that many men have tasted in the past. He moved the blade to her left nipple, caressing it without making any damage. Removing the blade he started to suck on Maria’s left hard nipple, taking her whole left breast in his hand while doing so.

Maria’s body was moving invitingly on the table, the man knew she was about to orgasm.
“Now it’s time for our game to start for real” he thought as he took the remote and increased the vibration in the brunette tight pussy.
The moans of the poor girl became louder, the man took her saliva covered left nipple and pinched it with his fingers and waited for the moment when Maria exploded in a wild orgasm, with a swift movement he cut her sensitive nipple free from her body.

A piercing and unbearable pain took Maria back to reality as she looked in horror at her left breast, blood erupted from the wound as the pain increases second by second.
“Too bad, no other men will have the pleasure to have a taste of this little one” he said as he examined the bloody detached nipple.
Satisfied he placed the little piece of meat inside a jar and moved to the other side of the table.
“Now what are we going to do with your right?”

Maria was still in shock from pain, the man could tell by the look in her eyes that she was begging him to let her go. “I cannot let you go my dear, your sexy body will be reduced to pieces when I’ll be finished with you” he thought

The man reached Maria’s right nipple with the scalpel “I’ve always wondered how nipples are in the inside… let’s find out” he says as the scalpel started to cut the still erect nipple vertically.
When the scalpel reached the base of the girl nipple and blood started to seep out, the man with his finger and thumb separated the two halves and examined the inside.

Maria’s body was thrashing against the bindings in sheer pain, she couldn’t believe that she will not feel her nipples harden in pleasure anymore, or the warm mouth of a man sucking it.

When the man finished playing with her bisected nipple he paused to admire his work: Maria sexy naked body trembling in fear and pain, blood covered her once attractive breast and keeps seeping out of the wounds with every heartbeat.

“This has been so much fun… I will get back to these later” he said as he squeezed Maria’s left breast drawing more blood from where her nipple used to be.
“There are so many parts of your body I can take care of… so… what’s next?”