Why do these things happen III

[789]

Okay, I have another advice question or whatever you want to call it.

My W, because of her job, wants to go in early every chance she gets, problem arise, or good thing if you want to look at it that way is....on the nights she is suppose to have S and wants to work early, she wants me to spend the night "on sofa" so I do not have to wake up 2 hours early and neither does or S.
It is a 15 minute drive, not bad, but sofa sucks and it is for her conveince not mine or S. Is this a way to use me, or a way to keep me around? The other thing is, if I do this, I will be spending 3-4 nites a week at her place, why the frick have 2 apartments..... ok done venting.