Out of curiosity, why is that a problem? I suppose he pays for both PPPoE accounts?
If each PPPoE client connects from its own MAC address and uses a different username, there is no way to find out that the two clients are used in load sharing mode, as the IP addresses you can see at their end are distinct too, so there is no common identifier at the client end you could use to correlate the two PPPoE connections to each other.
Instead of writing novels, post /export hide-sensitive. Use find&replace in your favourite text editor to systematically replace all occurrences of each public IP address potentially identifying you by a distinctive pattern such as my.public.ip.1.