My wife goes to town on my ass with a strap on everyone in awhile. It makes me cum buckets, and sometimes icum without and penis stimulation, just anal...

First trim your finger nails to the shortest possible! OR purchase a Prostate massager...or a dildo made for massaging a woman's G spot... Apply PLENTY of Water based lubricant or depending on the method used silicone lube. Then gently work the finger or dildo into the rectum. The "Spot" is located from 4 to 6" (in most men) into the rectum towards his balls/scrotum. It feels like a very small walnut size lump or ridge in side him. It is soft unless he has a infection (NOTE: if infection is present STOP). Infection can be spread by doing this and spread into the bloodstream causing serious health problems that can lead to death!
Once you locate the 'Spot" (he will know when it is found)...move your finger/massager gently back and forth side to side creating a smoothing sensation. gradually and GENTLY increase the amount of pressure as you progress. You should notice Pre-cum oozing out of his cock! This is normal and is called milking! Once you've gotten to this point, start moving your other hand up and down over his cock! However he likes to be "Jacked off" he should have an awesome ejaculation amount and a mind blowing, shivering ,shaking, leg flopping orgasm once you'd learned the right way to do this. For more info PM me.

After viewing your pics, I wonder why he would object. I certainly would not.