Good boy.
Surprised to see my cock?
Take out that butplug, make room for me.
Fix the dildo to the at knee height. Get on all 4 in front of it. Move yourself backwards till the tip of the dildo is in. You may lube if you want to.
(If you can't fix it to the wall: get on your knees, place the dildo on the floor and gently push it in.)
Once it is in, continu...