YOU CAN SMELL HIM FOR ODORS THAT ARE UNUSUAL.
WHY DO YOU THINK THIS? HOW LONG HAVE YOU BEEN THINKING OF THIS?
YOU CAN ASK HIM OR HIRE PRIVATE INVESTIGATOR FOR A FEE.
Answer2: The best thing you can do is sit down in a calm, dignified and non confrontational manner with your mate and tell him/her why you feel there is a third person in your relationship. Talk about your feelings and get everything out in the open and ask, are you having an affair. Wish you the best.