Will you get stretched out down there from masturbating?

I'm 16 and since my bf and I aren't talking we're obviously not having sex anymore. He always told me I should 'play around' and he even used to play with me with this vibrator he bought.. But he keeps it at his house cuz if my parents found it they'd freak and plus we were secretly dating cuz he's 24. But he was my first so I'm pretty tight and I want to stay that way!! He was 7 inches and said that I was still super tight every time he went in so if I use smaller things will I stay nice and tight down there? What makes you looser!?!