SCARY glitch

I was just playing minecraft with my buddy and suddenly, a duplicate of me came out of NOWHERE.

From my view, I see NO clone at all. But Darrin sees him... This is his screenshot.

[link]

This is SUPER weird....

It turns out, that as this happened, Darrin's computer started scanning for viruses. And MY computer got a pop-up... and I have an excellent pop-up blocker....

I'm scared....

ONLY GOD CAN SAVE ME NOW.