I have long suffered from premature ejaculation, this was very frustrating for me and also my wife. I have masturbated since about age 12. I know my wife masturbates, using a vibrator, especially if we haven't had sex for a week or so, usually due to an argument. We do not discuss masturbation. Since her first pregnancy we have used some form of mutual masturbation as our main form of sex. I usually to her first, sometimes with finger stimulation of her clitoris, other times using a vibrator on her clitoris. I particularily like to perform cunnilingus, with G-spot finger stumulation, which gives her a tremendous orgasm. Sometimes we do it in the 69 position with her mildly stimulating my penis with her hand while I do her to orgasm. After her orgasm is finished she will jack me off, I like to watch and usually get in the kneeling position so I can watch her hand going up and down my cock, encouraging her to stroke faster when I am about to cum.
Another variation is for her to get on elbows and knees, I slide under her on my back and do cunnilingus while jacking myself off slowly. When she is about to cum, I increase my stroke speed and we cum togather.