Wondering
 

You ever use this as a chance to slide a well lubed finger in her ass?

Yes, I have. It's funny, she doesnt want me to finger her pussy during these massages because she is afraid of the lotion giving her an infection but into her ass she is ok with. I usually will just pretend I slipped as I'm working right around her butthole and go in a bit. She doesn't complain as long as I don't go in too deep.