how to know if he is a cheater

The most common sign would be if he won't let you hold his cellphone.

1. Spends less time with you. 2. Lies about where he has been. 3. He is always broke. 4. He always takes 2+ hours to go to a store which is only 2 blocks away. 5. He comes back to your house with glitter on him. 6. Goes out with other women behind your back. 7. He has other womens phone numbers. 8. Can never tell you what he does during the day or where hes been period. 9 Tells everyone your just friends. 10. Cant Take you out to bars.

Well what I would look for in my mates IS NOT something I would suggest someone else look for in their mates because they are completely different ppl...In my husband I would look for him being very dodgie with me...something he really isnt inclined to do because of my temper and knack for finding out things even when ppl dont want me to....With the bf it would be his being distant from me when we are together...

Well, he looks very unusual. He avoid to discuss things with you, he made the talks very short and seems wants to be out of your site most of the time.

he hides his cp, he answer his cp like he's whispering, he stays online late at night, he goes home late from work, he spend less time with you, even if you wear sexy lingerie it does not have any effects on him, he mention a girl's name when he's sleeping, etc

Hmm. Sort of question whose answer will differ from person to person. If you know you your partner completely in-and-out then you can suspect if he/she is cheating if there is a big change in his/her behavior. He/She will not sound as always. If you have lot of bucks in your pocket, you can always hire a spy or you can personally spy on him/her. But I personally don't suggest this as this reflects your untrust in your partner.