What kind of relationship do you have with her? I stayed at my couple's house for about a month when I moved to a new job and to be near them...until I was able to find a place of my own. I also spent a few weekends with them before moving and a long week camping with them. I must say it was awkward at times knowing what was expected...or what would be helpful. They had their routines. She had her routine. I asked her what would be most helpful in terms of housework, etc. But there were times I felt like I was just getting in the way of her routine and way of doing things.
So, while I can see how she/they interrupt your routine, as someone whose been on the other side of the situation, it wasn't exactly always comfortable for me either. I am jealous at times that they have a place together, live together and are able to have routines and a life together. Being the "guest" has its drawbacks. (He couldn't come to my place when I lived 7 hours from them due to their work schedules. I had more time off, and she has a 9 year old son that he cares for during the time she's working or going to college.)
As for meals....HE cooks for both of us!
We will take a meal he's made to her at work and all eat together at times. And I'm free to rummage in the cupboards or refrigerator and get myself a bowl of cereal or make a sandwich if I'm hungry. No one has to serve me.
I "visited" for the weekend last weekend. On my way to their house I called and asked if there was anything she needed/wanted snack-wise at work since I'd be driving right by where she worked. While at the house I did my laundry and theirs, bagged up the trash and took it out, put fresh sheets on the bed when I arrived and took them off and put them in the laundry just before I left, unloaded and reloaded the dishwasher, hand washed and dried a few pots and pans that I hadn't had meals from, and wiped down the countertops and stove top... while he was at a choir rehearsal for 4 hours. I also watched her son during the time he was gone since she was working.
I don't know what to recommend in terms of overhearing their amorous adventures. That's a tough one. I'm a rather noisy lover and in all honesty it's no fun having to hold in and suppress myself, but I do it when she's around. (And I guess she really wouldn't mind overhearing us as it's kind of a turn-on for her according to him....but not for me knowing I might be overheard!) Also....your guy's other woman isn't responsible for the fact that you're not getting your sexual needs met with him.
Perhaps if talking to him doesn't seem to help much...you could approach her about some of this?????