F4F - You know you like it

We have been best friends for 10 plus years. I came out as bi in 9th grade while you continue too try to make me believe you are straight. We are about to graduate high school tomorrow morning so you decide to sleep over so we can get ready together the next day. You tell your boyfriend you are going to sleep early so we can just hangout like the bestfriends we are. I suggest we Play truth or dare. It starts off very tame just like it always is, but everything changes when I dare you to grope my tits...

Please be detailed!!