Your sister has a suggestion.

'Because if you don't have an idea, I do'

"Ha, and is your idea that I let you go?"

Andrea rolls her eyes, and writes out 'I know you are not going to let your your cock out of a mouth until you are good and ready, but my jaw really needs a break, and I would like to explain the idea to you verbally instead of trying to write it out, so when mom gets home can she and I switch places just for as long as it takes me to explain?'

"Let me think about it, for now go back to the relaxing blowjob."

You lean back into the corner of the couch, throw your hands back behind your head, and stare up at the ceiling. Your sister has been a bitch your entire life, and despite what ever she might be thinking, today is about putting her where she belongs, "I don't know sis, I don't see why you can't just describe what you want by writing it down. I mean besides the possibility exists that you and mom might leave part of the head of my cock open to the air, and we both know that wouldn't be done on purpose. I just don't see why we should take the risk, because... we... we don't want to find out what will happen if I can't cum..."

You feel your sister grab the paper and begin to write, but at this point, well you are just enjoying the feeling of your bitch of a sisters tongue sliding along the bottom of your cock. You kind of zone out, almost a meditative zen, but then your sister is tapping you with the notebook, and you have to jerk your head to look down at her. "Damn it Andrea, I was completely relaxed, what do you want?"

'Fine, I'll tell you the idea, but I'm not explaining the why by writing. The Idea is for you to cum down my throat, your dick as deep in as it can go.'

"But, no you are going to have to tell me why." and then the notebook gets tossed across the room. "...So I take it this is your way of saying 'this conversation is over' pretty effective, well Mom is already an hour late, I'm going to take a nap wake me up when she gets back." lying your head back into the corner of the couch you close your eyes and focus once again on the feeling of your sisters tongue, but with a small change, your sister appears to be attempting to **** your cock into her throat on each down stroke, but the enforced slowness of the blowjob isn't letting her work up the speed she needs to get past her gag reflex.

"Well gagging yourself on me feels really really nice. the sounds you are making are not relaxing at all, kind of defeating the point of the 'relaxing blowjob' so stop it."