ESTJ + ESTP

Both share very similar personalities - enabling them to easily understand where the other is coming from.  ESTJ's are more traditional in nature (usually politically conservative), while ESTP's are more liberal.  However, there are many other ways in which these two connect on base levels.

The main differences in personality lie in their preferences for (J)udging and (P)erceiving.

Judger's (especially ESTJ's) are strongly opinionated, organized people.  Think Army General.  Perceiver's (ESTP's) don't like being pinned down by schedules, don't like being controlled by others and according to many ESTJ's, are too carefree in attitude.  These few differences will be the crux of the frustrations between the two.