Not thinking it through and being lazy. I usually lay over a hassock or footstool to help with the weight on my back if he knots/ties with me. So ya know I'm 5'10", 150lbs, the rottie was 200+ if an ounce.
I was on my knees with my chest on the seat cushions of the couch. It seemed comfortable enough. My friend brought the rottie in and asked, are you ready? Oh Yeaaah! My smartass response. She cut him loose and ran straight to me and jumped on my back. It was at that moment that I realized maybe I wasn't ready. His weight had knocked the wind out of me. I hadn't been with one this size. His cock poking at me felt like a broomstick. When he found my asshole I almost whited out from the insane pain of more inches than had ever been in me before was slammed balls deep in me, then over and over. I felt his knot swelling in me and was wondering how big it was and if it would tear me apart. Not that it would matter, I'd given up on getting loose til he was done as I couldn't hardly move under him. It was the biggest knot of my life and it kept growing, stretching me, pushing on my prostate. I could feel it throb as his cum went through it, then his cock flex as it pumped the cum deep into me. In a matter of minutes after being knotted I pumped my load out onto the carpet. I have no idea how long until he was done with me and pulled loose. My friend said, that was intense! Are you okay? Yeah, once I can walk again I'll be fine
Lesson learned and it could have been far worse....