It is... and not wishing to put anyone off it did break once...
It went in my cock super easy so i felt comfortable going in deeper... but i was so massively turned on by the sensations my cock got harder and harder like it was pumped lol...
Turned out my "straight" dick has a slight curve when overstimulated and it was enough to snap the glass (really.. dont try it at home folks!)
Thankfully it was a totally clean break, the protruding bit came out reaĺy easily.. but panic set in as i worried how to extract the rest safely...
It felt like a long time but adrenaline does strange things.. and it was probably only seconds.. but i had an overwhelming need to pee and i realised as long as i didnt push it out.. it would be fine... sure enough as i relaxed the piss helped carry the remaining piece out with no damage whatsoever..
Now i only play with that glass one superficially.. never all the way in