Yes, it is going to happen. Reach back with 1 hand and place that toy against your pussy, close your eyes, push yourself on that big dildo!
Slowly let it slide in you and if you are used to the feeling then ride it in and almost out. Fuck yourself like this for 10 min and try to get to the point of coming with only that toy inside you and both hands on the ground. Keep reminding yourself who placed you in this position while you feel that huge thing inside you moving in and out.