then there was also one of my friends who tried to spit straight forward while riding on a bike. it flew back and hit his face (not my most clever friend
)
in physics, one learns that if you spit forward whilst already having speed (on the bike), then the speed of your spit would be equal to the speed of the bike + the speed with which you released it from your mouth.
unless your friend installed nitrous boost on your bike, the phenomena you stated is impossible.

this applies on any object with speed. if you are, say, riding on the top of an aeroplane travelling at a few hundred metres per second, and then you jump straight up, you will actually travel the same horizontal distance as the plane. This means that when you land, you will still be on the plane (at roughly the same position as when you first jmped up)
and i think spitting on the street is bad
