Yes it's possible to break one's penis, and its very painful, it occurs when an erect penis is thrust against a harder object or surface.
it's a medical emergency and you'll need a surgical intervention to repair it.

i have a close friend who had this real bad experience when he was making love to his girlfriend,

Do it soft and slow !!!

Yeah it's very painful,
Some pictures :

A fractured penis requires urgent medical attention. If untreated, the injury may result in an erectile dysfunction : deformity of the penis or the inability to have or maintain an erection.

Actually, only bones can break, the penis has no bones. So technically it can't break. You can tear the muscle in your penis though. Which is very painful I can imagine

what is my mother's name?

sherly