Drawing Pictures

We have a wide variety of foreplay and masturbation techniques. Here's one of them. This one is more often a form of masturbation than foreplay. It started because my wife told me that when she was a little girl her father used to 'draw' pictures on her back using just the tips of his fingers with a feather light touch. Absolutely nothing sexual about it, she was well pre-pubescent, and he was a really good guy. Just warm, innocent father/daughter contact. She said that her memory of it was that it was a wonderful, relaxing delight. Like having the nape of your neck softly stroked. She said that now she was adult, she would like to re-create that feeling and that it would relax her, and might now lead to more interesting things. We were in bed, naked (we both sleep naked). She turned away from me and lay on her side, and I spooned her, but separated at what Americans would call her 'ass', forming a V shape so that I could get my arms and hands between us. I then proceeded to draw pictures on her back with my fingertips with a very light touch. A combination of touching her naked back and the sense of anticipation soon caused me to get an erection. She could feel it against her lower back, but said nothing, and just enjoyed the sensations. After a while she sighed contentedly, and asked me to put my cock between the cheeks of her ass while I continued to 'draw'. Almost imperceptibly she pressed back against me so that my cock made firmer contact. Then she whispered "I'm ready now", and opening her legs a little, reached between them, and pulled my cock through so that it rested against her pussy. Holding my cock from its underside, she began to rub it against her pussy, and also began to move her hips a little. She was masturbating, using my cock. I continued to touch her back while she masturbated until she made herself cum. After she came down from her orgasm, she turned round and masturbated me to orgasm describing the sensations she had enjoyed. It is a technique we have re-visited countless times since, with some variations. On one occasion she arched her back while she was rubbing my cock against her and pushed it upwards into her aroused pussy. She rubbed her clitoris and made herself cum with my cock in her. But that only happened once. On all other occasions she has used my cock on the outside. There have been plenty of variations on what happens after her orgasm, including the 'usual suspects' - intercourse, cunnilingus for a second cum for her, and more hand sex. She has always said that the drawing pictures phase is exquisite, and sets her up for some really memorable orgasms.