comon hon
u know that after sex the vaginal muscles are tired and are more "lax" than if a woman goes without sex for a few days.
Its simple. as men we learn to feel how our girls pussies squeeze our cocks depending on when the last time we had sex with them was. It is OBVIOUS to us(the difference that a few days or weeks makes in vagianl tightness). So if a few weeks passes by and we have sex with our girl and it feels looser and wetter than usual then obviously she has had something up in there to tire out the muscles.
its just like if you do a few yoga classes, you retain flexibility for several days before you tighten up again. the vagina is the same way.
end o story.
moral: Guys, pay attention to your girls gash. if you havent ragged it out in awhile and u hit it and almost fall in. the bitch is cheating on you. take it from someone who has been there and called the bitch out on it.