Apparently the human anus can stretch up to 5 inches in diameter (2.5 inches radius). A sharpie marker is roughly 11mm in diameter (.433 inches). Math shows we’re a long way from the max record!
Wanna play with me? I make custom [vid]s, [pic]s and [rate]s, or we could cum together on a [sext] session that includes pics and short clips, also there's my [gfe] were you could stay with me as long as you want... ;)