big mistake lots of men make: don't tell her she is pretty or she will get a big head ego

 men when you do this you are on the fast and

sure path to losing the woman you are with

there are countless men out there that know the score and

will snatch up your woman in a heartbeat

simply by being appreciative /appreciating her

while you mistreat abuse her ignore her 

deny her simple things like politeness and affection

and be rude mean nasty impolite inconsiderate (a total JERK)