In that case, an option is to create your own account on one of these sites and then search for their physical attributes (age, hair color, etc) and location to see if you find a matching profile.Many sites and apps (like Tinder) only allow people to see each other based on location and mutually matching search criteria (like age and sex).Facebook's People Search lets you search for people by filling in one or more search boxes: Name, hometown, current city, high school, mutual friend, college or university, employer, and graduate school.If you know one or two of these things about your subject, you can narrow down your search and then browse through the photo results.If your subject has no social media presence, try to find their friends and family members; it's possible they're hiding their account behind a fake name.If you have no idea who their friends and family members are, and you know their full name, use a free people search like Intelius to look up relatives..then hunt down those relatives.For example, if you know your subject's name, job title, and location, you can probably find their Linked In profile.On their Linked In profile, they've probably listed their undergraduate degree and when they graduated from college, which means you can work backward to figure out approximately how old they are.
Fortunately, these sites aren't necessarily as anonymous as would be adulterers and cheaters would like to believe.
If no social networks pop up in your initial Google search, you may need to go into the social networks themselves.
Facebook is the most popular social network, and it has the most robust search engine, so you should probably start there.
If all else fails, you can hire a professional investigator to find out for certain whether your signifigant other is using a dating site.
The first step is to be aware of common dating sites and apps (many of which are intended to look inconspicuous) so that if you stumble upon them on a shared devices's apps or browsing history, you’ll recognize them.