During the first year or so we were married, my wife didn't want sex during 'that time of the month', so we both did without for those days. (We had been active for some time before we got married, hand and oral at first, then everything, so it wasn't like we didn't know about alternatives - we just did without.)
But one month she developed a yeast infection that took several days to clear up, and just as she was almost 'back in commission' her period arrived, and our activities were once again on hold. On the second night, fortunately for me, she sensed that I was desperately in need of some relief, and as we got into bed she stripped to just her panties, and suggested I strip completely. I did, and as always, the sight of her body got my attention quickly. (Let me note here that she was slender, with soft, nice, B-cup breasts - not large enough for what one typically imagines for 'tit-f***ing'. Her nipples when aroused were pencil-eraser sized, both in size and shape - very suckable, in my opinion. Too, the rest of her body was easy to look at, even with her panties on.)
She told me to lay on my back, and she in turn lay beside me with her left breast on my leg next to my by now very aroused penis. Slowly she reached out and began caressing it and rubbing it against her breast. 'Mmmm,' she said, 'it feels so warm...'
I was certainly enjoying the feel of her hand and her breast, and let her know. She simply smiled and continued her slow stroking. Within a minute or so I was leaking pre-cum, and because I'd done without for several days, it quickly became a LOT of pre-cum, which she rubbed onto her breast and nipple. Of course, this aroused me even more, it was the feel of my cock rubbing on her slippery breast that was my undoing. In short order I was spurting what felt like a gallon of cum onto her chest and both breasts. The feeling and the sight were both incredible, and all I could do was moan as she milked every last drop of my load out onto her skin.
'You did need that, didn't you?' she grinned as she let go of my softening cock and used both hands to rub my cum into her skin and breasts. When she finished, it seemed only natural that I taste her cum-covered breasts, which she enjoyed as much as I did.
From then on, when 'that time of the month' arrived, we enjoyed our version of what she laughingly called 'tit-f***ing with small tits'.