What Causes White Discharge After An Intercourse?

Hi, Im experiencing some thick white discharge its not a little white is is as white as a whiteboard its not coming out into my underwear only after sex when my byfriens penis is covered in big clumps of it. It doesnt smell and i have no burning or irritation although it is difficult to have sex as im not getting wet? no amount of lubricant can help the dry rubbing sensation i get duing intercourse.

can you help?