Make her get you a beer.

"Honey, crawl over to the kitchen and get me a beer."
Your wife looks to the ground and gets on all fours. While crawling you look at her nice and firm ass bouncing all over the place. By the time she is back you are hard again from all the thoughts.
"Don't hold it in your hand, grab it with your mouth stupid."
You command her and she obeys. A small "Sorry" escapes her mouth.

She comes to you and drops the beer at your feet. Then she looks up and awaits her next command. You grab her hair and pull her hair towards your balls, without much regard whether she has her balance or not.
"Lick!" You command.
She starts to lick and you pull her lips down to your balls. Now she is licking your balls while you're jerking off in her face. You look into her eyes and feel your dominance rise.

"Get on all fours again!" You command.
She obediently gets on her hands and knees facing you. You stand up and walk behind her. You kneel and give her ass a nice slap. Then you feel her pussy and notice she is wet. Seems like she enjoys servicing you. Now the question is, pussy or ass?