Save Your Ears, Save Your Reputation
One feature of the video as made on the DSLR is the lousy sound. This is a blessing as it disguises the voices.
Should you, as an iconic video master, wish to avoid the wrath of the sister and the contempt of the crowd may we suggest that you buy your own set of professional headphones and an adequate professional microphone. Sennheiser have these and we have them in-store right now.
The MKE 600 is such a microphone. Super-cardioid pattern, 40Hz to 20kHz, max SPL 138 dB. Comes with stand mount and wind shield. Pro quality and clean sound.
You can hear that clean sound - or at least hear how bad your mates sound - on the Sennheiser HD 28o Professional with its high passive noise attenuation. you will be able to hear whether you are making too much noise operating the camera as well. Beware.
If it all sounds dismal, take heart. Learn to draw cartoon mice and dress them in white gloves. It worked for Walt and it can work for you.