There are two changes to look for here. The more obvious one is that if your man is seeing someone else, he may not be excited about sex anymore. If your sex life has been dwindling for a while, then not having much sex doesn’t mean your man is cheating, but if he used to be excited about getting into bed with you and isn’t anymore, it may be a sign that he’s getting it elsewhere.  Another change you may notice is that suddenly your man has an insatiable sexual appetite. This may mean that his sex drive has become more intense because he’s sleeping with another lady. See what he’s like in bed. Is he suddenly much more adventurous than before? Has he always stuck to the same routine and is he now trying to spice things up every time you get into bed? He may be getting his moves from another woman. You should also see if he’s suddenly shy with his body around you and doesn’t want you to see him with his shirt off. If he only wants to have sex in the dark, then it may be because he does not feel right about sharing his body with two women. He may be much nicer to you because he feels guilty for being unfaithful. If he’s been distant or uncommunicative, or if he just isn’t a very demonstrative person, but he’s suddenly being very kind and sweet, and always telling you nice things, then it may be because he’s trying to compensate for seeing someone on the side.  But then again, he could just be being nicer because you are going through a rough patch and he is trying to make it up to you. If he suddenly brings you flowers, chocolate, and sweet cards, he could just be trying to be bringing back that loving feeling. Alternatively, he may be compensating for cheating. If your husband is not normally too handy around the house, but now he’s doing the dishes, doing the grocery shopping, or even doing the cooking, then something may be up. He’s certainly trying to compensate for something, and it may be cheating. But again, maybe he’s just trying to be nice suddenly, or wants something else from you as a result. Still,...

TL;DR in Indonesian:
Amati apakah ada perubahan dalam gairah seksual suami Anda. Perhatikan apakah suami Anda tiba-tiba selalu bersikap baik pada Anda. Perhatikan bila dia tiba-tiba sering membantu Anda di rumah. Perhatikan perubahan suasana hati suami Anda. Perhatikan perubahan pada cara dia memperlakukan ponselnya. Perhatikan kebiasaannya dengan komputer. Perhatikan alasan yang dia berikan pada Anda. Perhatikan kata-katanya.