She has great, suckable, tweakable nipples. She can almost cum just from rubbing her palms in circles around the very ends, or pulling them like she's trying to get milk, or me sucking and using my tongue to circle them, or flicking the tip of it back and forth across them.
We were just playing around one time and I rubbed the head of my cock across her nipples. All it took was a minute or two of that and then a couple of quick strokes with her fingers across her clit and she went off like fireworks. Then I continued, making sure the underside of the head was the main contact point until I shot a flood of cum across her nipples, tits, and belly.
She hadn't really considered licking or sucking them until I encouraged her. Now it's a regular part of her activity, either with me or masturbating when I am absent from the house.
In the "Attached Files" box is a clip from another time of her taking charge and working the head of my cock on her nipples, making use of the leaking precum. Unfortunately, I am not technical enough and the clip is about 15 seconds too long. Anyone is free to see what can be done about that.