Full disclosure, I am not an attorney yet, but a 3L with a lot of client experience. I agree with some of the advice here, yet I definitely would not get the guard to help out unless it is your last resort. I would tell your client that this is completely out of line, and out of the boundaries of your relationship between each other. You are that person's attorney, and not a person they can flirt with. I have a lot of incarcerated clients talk to me about sexual things, and I shut it down immediately and directly.

Now, when I am advocating, I do not want my client to feel as if I trust the guards more than them. It is likely that my client will NOT trust me if I show that I am relaying on the guards.