Infuriating Mothers and pent up sexual energy

The two together are making me one cranky mother fucker today. I've been dying dying dying to wank ever since yesterday and not being able to is driving me insane. To put it plainly, I need to come and I haven't had a minute to myself in which to do so. Last night I spent over an hour awake in the middle of the night, pent up sexual energy driving me insane and thoughts of filth preventing me from getting back to sleep. However as my mother was in my spare bed near by I obviously couldn't do much about it and today she has driven me insane. We went christmas shopping which was good in itself, but what drives me mad is that she lacks common sense and you have to explain the simplest things to her a million times before she understands them. I tried to tell her to get an Oister card today and we had the following conversation.
Me: "You have to touch in an out at each tube station."
Mum: "Why do I have to touch in, they hardly notice if you do or don't."
Me: "Because if they then make you touch out at your destination you'll get charged the maximum fair."
"Why? How will it know I've been anywhere at all, I could just be coming in to the station for all it knows."
Me: "Because you're touching out, not in and because it doesn't know where you've come from it'll charge you the maximum fair."
Thinking this was all explained and good we bought the Oister card, only to have her not touch in and then have the same argument with me over again until I got so het up that I just said, "for fuck's sake mother! Just swipe the bloody card, it's simple enough, otherwise it'll use up all the money you've just put on there." My mum being a tight arsed northerner didn't argue with this conclusion, I think she would have died if it swiped the tenner she'd just put on the card. We had similar arguments over different things throughout the day but I can't really remember what they were about to tell you now. One other was about tube lines, she didn't seem to understand why we had to change tubes and that it's not just all one big line of tube stops. She's been coming to London long enough to know by now surely. So we arrived home after five hours shopping and I just wanted to quietly check my emails and have a cup of tea and she's there going, "feed the dog, the dog needs feeding, put the TV on, what are we having to eat, feed the dog, put the TV on." Aaaaaaahhh!
Although I do love her obviously, I'll be so glad when she goes for a hopefully long shower later and I can have some time to myself. She's leaving tomorrow afternoon and I get the feeling tomorrow will be just as stressful, especially if I don't manage to make myself come in the short space of time I'll have later. Oh and another thing, she's also discovered the wonders of facebook and I had to spend the entirety of yesterday evening showing her how to use it and setting up her profile so that she could, wait for it, go and look for good looking men. She's worse than me I sware!
Ok, enough ranting, I'd better post this before she comes back from smoking her cigarette and talking on my phone in the kitchen. Give me strength!
PS: she is now going through my dvd's trying to find something to watch and she just said, "what is Closer about?" "You've seen it mum," I said. She stared at the DVD and said, "I can't remember it." "Well you have," I said. You can garantee she'll insist on putting it on and ten minutes in she'll say, "Oh yeah I have seen this haven't I."
Oh, and one last thing that has infuriated me today? My phone keeps beaping like I have a text message, and when I check it, there's nothing there. So either my phone is fucked, or I have a serious case of hearing things.