Hi Shesoshy,
The P spot is located inside the rectum. You can have some success massaging the perineum. This is limited the best access is go up the rectum about 2 inches with the pad of your finger point toward his top. If he is on his back and you put your finger in his anus have the pad of your finger up. You will want to feel for some thing about the size of a walnut and start out slow and gentle. You will have to experiment on what will feel best. Like a come hither movement, circle movement or just back and forth until you know and you will know. He will let you know whether or not he speaks. Consistent movement is important. Plus lots of lube there is no such thing as to much. Plus don't be concerned if he does not have a hard on because this is normal. You are working on a deep orgasm like a gspot orgasm for you. Lost of pre- cum is normal, but can be different for different men. Some more some less, but you could see the largest amount ever. Have you done anal play before? If not I recommend you read up on anal play first, any more questions just ask.