This is more like a technical description than a story:
Couple of years ago I had an experience with a gothic style girl who had enormous boobs. I already had several titfuck experiences with one of my ex gfs who had a D-cup, but his girl had literally boobs bigger than basketballs, and the best of all, she wasn't fat but just chubby. Pretty average face, but she wore heavy and sexy makeup and had a "madonna" piercing on her upper lip, which really turned me on for some reason.
To be honest, titfucking her was quite difficult. With my D-cup ex, I could easily do it with my 17cm (~6.7 inches) penis in several positions, which of course made me think it's as easy with her, too. However, it was practically impossible to do it when the girl was laying on her back and I was on top of her. The boobs were just so huge and heavy that holding them up was quite uncomfortable although the girl was helping me. I also felt that my cock was just too small for it: there were also absolutely no change to get the tip of my cock into her mouth/get her lick it during the titfuck as my ex often did.
Then she asked me to sit on her sofa and began to slowly deephtroat me (this was actually my first time I got really throated and I had some big troubles not to cum too early). Then she lift those huge boobs on my lap and salivated on my alreadly sloppy cock and her tits, and then began massaging my cock with her boobs. It felt and looked so good I can barely describe it, and once again I had to control myself not to cum too early. Still, it was impossible for her to lick my cock at the same time as the tip didn't even show between those boobs, but she sucked my fingers and kept a very flirty eye contact which was quite hot. Then I took the boobs on my hands and she began to slowly rub my nipples with her fingers. At that point it was impossible to prevent cumming and I just let it happen.
That was some experience to remember, but still I can't imagine how satisfying that would have been if I had very strong arms and had a 9 inch cock. Better for the guys of my size to stay with the D-cups. I had sex with her three times during the few coming weeks until it got really messed up and I had to stop seeing her.