She had gone in for a free consultation with a doctor to discuss the difficulty she’d been having letting men use her asshole. She was incredibly tight and it not only hurt her, but also their cocks. He suggested a regimen of brutal anal fucks by large, hard cocks, twice daily until she was stretched out to a useful level of tightness. He had her come in once a week for an ass-fuck to make sure she didn’t get too loose, since it was important that she be tight enough that she’d feel the pain of being ass fucked by a normal cock, but not so tight that the man would be uncomfortable up her ass. She thanked him with a blowjob at the end of every session.