funny you bring this topic up. ive had 6 partners and i have noticed that i think ive become looser. i think that you just loose the tightness once more and more penis goes up there. so i would imagine that a dildo is equal to a penis??! i think there are exercises that you can do to strengthen the muscles down there. something like when she goes pee, tell her to clench her muscles about 10,20, times (the muscles she uses to pee). sounds gross but i guess it works. but hey, its going to be ok....dont freak out! lol