A sensation of weight on your back, a strong breath at the
back of your neck are all very strong evidence of piggybacking. I
would advise you to turn round and check if it IS him. It could be
someone you don't even know.

This kind of letter is very ill advised in this forum, you
will soon draw the attention of people with funny names like
"asslovers" and such, beware.


On a more serious tone, just fire up wireshark and SEE who is
using your network. You feel there is someone there, sniff and see.

FWIW