When an un-trusting chick doubts that you have climaxed. So while astride your manhood she continually grinds your already swollen tender penis to be sure you have blown your load
Dave - Man, that Susie sure is one mean bitch. I totally lost a load inside her and she wouldn't stop riding me!!
Steve - Dave you wanker! You should never try to lay Susie, she's one of those excess riders!