As you may or may not know as a women approaches orgasm her pussy muscles contract and squeezes the penis inside her, a big cock would usually make her orgasm more quickly, that same big cock give her something substantial to grip and squeeze down on making her pussy feel tight to them, that's what makes them cum quickly. Because she was use to having a huge cock inside her to you she feels loose and sloppy, that's not her fault, its gust that you are not equipped well enough to give her the stimulation to squeeze your little cock, that's all