G String Try On JOI. In this jerk-off instruction video, I try on various pairs of g-strings and tease you with my 38-inch bubble butt. I love teasing your cock and telling you how to stroke for me. Which g string is your favorite (I try on four pairs)? They are so skimpy and show off my full bush beautifully. This scene ends with a hot cum countdown; you better make it to the end!.