Increasing girth is possible and you can get easily a 8 inches girth by stretching your dick for a long period of time, say 5 years, one or twice a week. Stretching must be very careful at first, as you can damage veins or vessels, but once you have got a very remarkable girth say 7 - 7.5 inches you can stretch your dick without any problem, until you get a monster girth. No fellatio sorry.