It's quite possible indeed. One love was too big and my being on top was not something we could do quickly, but when we took our time, it was great. Another simply was too big. Period. Luckily, there was no chance of being bf/gf, so, no great loss there.
Vaginas do stretch, this is true-they have to! But, some of us are not only tight, we're short inside as well. Lube won't help that part of the problem, but
taking your time, knowing what you can handle will. And that's the key,
don't rush it, let your natural juices flow, use lubes or oils if you have to, experiment with positions, experiment alone as well to know how you are 'built'.