codenameone sequential socket write/read

I'm trying to implement a SMTP protocol in my app, but I have a problem doing more than 1 write/read on a InputStream/OutputStream using codenameone SocketConnection.
This is what I have so far:

Socket.connect("<google ip>",25,new SocketConnection(){
    @Override
    public void connectionError [...]

    @Override
    public void connectionEstablished(InputStream is, OutputStream os){
       try{
          BufferedInputStream in = new BufferedInputStream(is);
          BufferedOutputStream out = new BufferedOutputStream(os);
          byte[] response = new byte[1024];
          String z;
          int size;

          out.write( ("HELO mydomain.me").getBytes() );
          out.flush();
          size = in.read(response);
          //in.mark(size);
          //in.reset();
          z = new String(response, 0 ,size);
          System.out.println(z);
          response = new byte[1024];

          out.write( ("MAIL FROM: <myaddress@bubu.me>").getBytes() );
          out.flush();
          System.out.println("I get here!");
          size = in.read(response);
          System.out.println("I NEVER get here!");
          z = new String(response, 0 ,size);
          System.out.println(z);

          [... rest of SMTP that I never reach ...]

       }catch(IOException ex){
          System.out.println("I don't even get connection errors");
       }
    }
}

This is the output I get:

220 mx.google.com ESMTP [...] -gsmtp

i get here!

And the program get stuck here.

Which means the "HELO ..." and its response works fine, but then it get stuck trying to read a second time from the BufferedInputStream.

I have tried to switch from BufferedInputStream to InputStream, all combination of in.mark(size); , in.reset() , reading only a fixed amount of bytes (in.read(response, 0 , 200)), but I did not manage to make it work.

What could I do to fix this?