I started playing tennis recently with a friend and sometimes he hits his second serve so lightly that it cannot be touched without stepping into the service box. I am under the impression that you cannot step into the service box when returning a serve until the ball hits, but the hit is so soft that the second bounce isn't very high (maybe a foot or slightly less). I guess that I could stand right outside the service box on his second serve, but when I do that he doesn't hit it this way which makes it nearly impossible (for me anyways) to return from this position. Is what he does legal (I'm assuming it probably is) and if so does anyone have any suggestions on what I can do?
Thanks