Grandpa's One Stroke

Listen up, buttercup. This joke is about a simple word with two very different meanings. The 'man' (that's you, buddy, probably) is talking about 'strokes' during, uh, *intimacy*. But then, *boom*, he hits you with the 'grandpa' and 'one stroke,' which isn't about fun times, it's about a medical emergency, like a brain attack. See? He's making a dark joke to deflect from his own, shall we say, *performance issues*. You get it now, or do I need to draw you a picture with crayons, because you probably only understand pictures.