Change in Appearance

• If you notice your boyfriend making a lot of changes in his appearance, he may be trying to impress another woman. Notice if he is buying more expensive clothes or if he spends more time styling his hair in the morning. Also, be suspicious if he doesn't ask you your opinion on his new clothes.
  
  

Sexual Changes

• One sign of a man cheating is that he is different in the bedroom. He may feel guilty or want to avoid suspicion and show more interest toward you than he has before. Also, be leery if he never even brings up the subject of sex.
  
  

He Cancels Dates Often

• It is perfectly normal to cancel a date every once in awhile if you are feeling ill or you have a family obligation. However, it is time to be suspicious if your boyfriend cancels almost every date you two have scheduled. It is likely that he made plans with his other girlfriend at the last minute.
  
  

He is Distant

• Pay attention to the way he acts when you are together. If he doesn't say much and acts as if he would rather be somewhere else, be worried. Many boyfriends who cheat lose interest in their current girlfriends, but are afraid of hurting their feelings by breaking up with them.
  
  

He Doesn't Return Your Phone Calls

• In the beginning of your relationship, he called you at least once a day and always returned your phone calls. Now, he almost never returns your calls. If he always says he'll call you right back and doesn't until a few days later, it's time to be suspicious. It's a sign that he doesn't find you to be that important in his life anymore.