Light aircraft instructor pilot reported an NMAC with another light aircraft at BCV airport.

Narrative

I come from the west to enter a right midfield downwind for runway 20R ahead of me was a small aircraft landing on the parallel gravel strip 20L. The plane in front landed and it looked like it was about to exit the runway but then decided to takeoff right as I was conducting my takeoff after landing. He was at the very end of the gravel runway fully stopped which gave me the impression he was either waiting or about to exit. Lesson learnt never assume anything. I was conducting a touch and go. The plane in front ended up conducting a stop and go. As both planes became airborne we were almost parallel to each other at around 100 to 200 feet AGL. I started turning to the right to create some more spacing and shortly after I conducted an early crosswind leg. I reported on the radio that I was going to offset to the right and conduct a early turn. We got within a 100 ft. for a couple seconds. In my opinion the other aircraft should have reported that he was going to do a stop and go. As far as I remember he never did.