having fun with little time

if a girl want her boyfriend to ejaculate as quickly as possible, 

then she could try to relax her anus and rectum, 

and when he has pushed his cock inside her butt, 

then she squeezes her abdomen and rectum and anus around his cock 

and boyfriend will probably ejaculate quite quickly 

if she sits anal cowgirl when his cock enters her butt 

and then she pulls up her knees, 

so that only her feet touch the bed, 

which creates more pressure in abdomen and thereby rectum, 

then ejaculation could happen even quicker, 

just be careful when he pulls out his cock from her anus so that sperm is not farted out, 

could be better if he ejaculate in her mouth instead, 

while she has open mouth, 

or while she is sucking his cock