Switchable....
Interesting message....you refer to this as a three way massage. Seems appropriate....where I come from we affectionately refer to it as the "bowling ball" grip.
It has variations as to which fingers go where and how many in each orifice.
I know sometimes when I am about half way home, I will call ahead and request she greet me in the entry on all fours and if she is busy with dinner or distracted, she might whine a bit, but it almost never fails that when I open that front door, there she is....that beautiful round ass sticking up greeting me.
Often I can smell dinner being prepared and it is really relaxing after a hard day at work to come home and get my senses stimulated....visually that lovely view of her, the scent of food ....then her musky scent as I bend down close....my salivary glands making me almost taste what I know is waiting for me.
She is being such a good girl that I don't want to mess up her dinner so I take a little time and make sure I get all fingers in side somewhere and then, as you said my thumb on her clit. She's ready and willing and I know she needs to get back to her cooking, but I also know she has put things on hold just for me and I know how to make this good for her.
Her orgasm comes hard and fast and she mewls and smiles and when she cums, she looks back at me with this huge grin like a Cheshire cat that has just swallowed the bird.
She then delicately picks herself up and pulls her panties on and proceeds to finish dinner. I know that this has set the tone for a really nice weekday evening.