Ladies does large mean length or girth to you.
Which do you prefer?
Medically speaking (my field) a woman's G-Spot is 6 inches from her clit, so length wise all you need is 6 inches, Girth wise is most important as it's the pain pleasure threshold that gives you better orgasms. This is where anal comes in, providing a bit of girth to the anus can give you huge orgasms and even squirting due to the pressure applied by Girth. I also enjoy girth when in the mood for anal, although I'm generally straight I have found that my girth is just right (4 fingers) and I've never had problems giving a woman multiple orgasms. The other key aspect of build up and break down, you need to want it before it goes in. Use Tantra to make yourself hungry for penetration and when it happens you will be so wet, and It's just so much more enjoyable in general. Chemistry is key and always listen to your instincts no matter what your head says.