What Causes Loose Vaginal Entry?

Hi I am 21 and weigh 132 and I am 5'2.. and a healthy history.Hi me and my boyfriend have been together 2 years and for a few weeks on and off we used condoms. for the past 3 weeks we haven't...but last night we had sex and he said i smell like a condom. as if i had sex with someone else then him and that the entry of my vagina wasn't as tight as the day before. I have never cheated. what can this be??