To Have or no to Have

Reuters reports:

The German magazine “Men’s Car” found in a survey of 2,253 motorists aged 20 to 50 published in its inaugural May issue that male BMW drivers say they have sex on average 2.2 times each week while Porsche drivers have sex 1.4 times per week.

My biggest customer (in this case, ironically named Cock – he survived a vacation in Australia without an alias), has both. As I probably will pop the question later on today, I still need an opinion based reference to calculate the probability he’ll be lying. The question will be, in this case, should I average the number, or add them up ?