My teacher kissed me, dont know what to do?

ok, so my teacher always stares at me and tries to have conversations with me. when he pes me in the corridor, he always seems to graze past me and the other day he stroked my leg. so this afternoon we were alone in the clroom and i came to the desk and he just leaned in towards me and kissed me briefly and then just walked out? obviously i'm really confused, dunno what to do!!