You're a good daddy.
Honestly, most of us have the maturity of a seven year old. You might need to mute everyone though. In my experience, people use some colorful and mature (debatable) language liberally over the mic.
If your son knows how to talk smack, then it would be great if you could record yourself playing while he talked smack to the other players.
"OHHHHhh you just got Scoreboarded by a seven year old! Eat it, creampuff! Posting this game on the BSN, yo! My daddy told me noobs existed, but I thought they were rarer than unicorns until I met you, SON! Speaking of unicorns, which MLP pony is your favorite? I figure you like MLP, since it's as close to MLG as you'll get! OHHH SNAP! No I di'nt! Oh yes. I'm afraid I di'id.
Uh oh, it's nap time. Cya guys! GG no RE!"