Fresh from the Oscar-winning 1917, the actor is taking on his most challenging role yet. "There’ll be no more of this shit,” snarls George MacKay, eyes bulging like a young Iggy Pop. “I’ll give you the full 11 inches of my dick, just so you can know how it feels to get shaaafted!” His temple throbs. His mouth froths. He gets so excited that he spills some of his lemon and ginger tea on the floor of the photo studio we’re sitting in. “Oh dear,” he says, Iggy Pop transforming rapidly into an extremely apologetic, polite young man. “I’m just going to wipe that up with my bum.” And so he does – sliding across the floor while his black trousers soak up the drink.
This is from an interview with an actor and the full like is here: https://www.theguardian.com/film/2020/feb/29/george-mackay-actor-1917-true-history-of-kelly-gang-exhausting.
I don't know what the part marked in bold letters mean, especially the phrase "I'll give you the full ~ of my dick". I can only guess it's a sexual joke maybe to emphasize his feelings, but still I don't exactly understand what this means even after I've looked it up and there's really nowhere to ask but this website. Thanks in advance for your answer.