Look, I know I'm your sister-in-law, and this is really wrong, but I just secretly have a huge thing for you and by the looks of it, it seems you have a huge thing for me as well! So, how about we do something about this, and start with something small, like a jerk off instruction? I just want to see that big black cock you're hiding, but I don't want this to ruin our relationships! Why don't we both take off our clothes and just have some innocent fun? We can start by you playing with those beautiful balls, and slowly move up from there. Is it okay if I touch myself while giving you the instructions, and maybe have a little bit of a taste of it? Just the head, I promise! Well, maybe not, because that cock is throbbing for me and I can't help myself but ride it to both of our orgasms!