The second point - the extra costs. Mistress leaves too much money. This apartment rental, lunches in restaurants, gifts, etc. Smart man thinks - it is better to spend money on his girlfriend, whose tastes are known to please her, to get a guaranteed return than bestow passion, the reaction which can be unpredictable.
The third - a lack of willingness to lie and dodge. To change, you need to have an excellent memory. Have to remember that when it was told Standing woman what facts and reasons for the absence of the drive. You should also come up with an explanation strange calls in the night and reportedly controversial content. Too many have to keep in mind. A lot of men, up to their ears loaded at work, it just can not do.
Another important argument in favor of intelligent men of loyalty - health care. If a woman with a constant worry about it is not necessary - when paired trust and love, thoughts about sexually transmitted diseases do not occur - that with his mistress probability of catching something there. After all, if it is found not hesitate to free men, not the fact that he was her only one.
After weighing all the pros and cons, thinking man is unlikely to left. He better do everything to bring back the thrill in the relationship with your beloved than to risk the health of your family and for the dubious pleasure.