Honestly not a boast (because I'm only not that much longer than average at about 7 inches), but because an early girlfriend of many years ago was a tiny 4 foot 9 inches only(!!) she had real trouble relaxing and enjoying sex because of risk of over-penetration. I'd try to use only two-thirds of my cock but my enthusiasm and our shifting about always ended up giving her a painful STAB IN THE CERVIX so she'd be tense and close her knees together if I used much more than half my cock at anything near a frenzied pace. Not very satisfying for either of us. We tried reverse cowgirl, etc, but it's really never going to be good fucking when you're 7 inches and she's only good for about 6 inches. Tiny pussy, & tiny mouth too, so my relatively large cockhead was about all she could stuff into her mouth and she caught her teeth on it if she tried bobbing on it.
ANAL TO THE RESCUE! When our mutual (female) friend suggested anal intercourse as a thing to try for these circumstances I thought she was nuts. Too big for her pussy must surely mean too big for her ass? However, it is medically a fact that although an ass is tighter, it can accommodate much longer cocks. An average woman can comfortably take 7" in her vagina (when stimulated), but she can take two more inches up her butt. For my Robyn, being smaller she'd be at least an inch shorter than both these penetration depths, but still leaving enough depth for me to give her full stroke butt-fucks even if not vag-fucks.
Turns out Robyn had actually done anal before (I hadn't at that stage !!) but it seems not many girls volunteer it so she hadn't offered it to me as an option up till then.
I got to learn that alcohol, significant cunnilingus, slobbery tongue-assault on & in her puckered hole, wetting it, fingering it, lubing it, then butt-plugging while giving her a half cock-length pussy fuck, was all good preparation for steadily, increasingly vigorous anal intercourse.
It extended the life and quality of our sexual relations. I found there's nothing quite like 7 inch cock full-stroke bum fucking of a small girlfriend. After good prep, she really did usually enjoy it almost as much as I did!
ANYONE else had similar relief they couldn't get through pussy sex through incompatible sizes?