First Timer ( Help )

Okay so me and my friend have been experimenting with each other so we can get it all out of the way. The last time he fingered me he found my A-spot and it felt good but I would grab his arm to stop him and he would be like what's wrong and I'm like nothing and he's like so why are we stopping and I wouldn't have an answer so he would just do it again and go harder. Now I'm on my period and we can't do anything so were talking about what we will do next time. And I'm going to let him have total control. He's gonna tie me up ( so now I really can't stop him ) and I was thinking of being blind folded to bring more suspense.

Part of me is ready because I have always wanted to do this so I know if I like it but there is another part of me that's scared because I'm going to be little someone have full control. Any tips or things you like that I should try.