I have started to be interested in human relationships of any kind just recently, so I am basically entering a new world. There is something I am wondering.

I have started to notice many (= at least 4 in the last month, which is a lot given the restricted social circles I have) "couples of friends" that look too close to not be suspicious to me. These consist in a guy and a girl who are friend, who don't do anything clearly saying they are in a relationship (e.g. no lips kissing in public), but look so close and frequently delve in borderline behaviours (e.g. hugging, sometimes hand-holding, occasional teasing, several IOIs from the girl to the guy...).

I am wondering, how many of these are actually hidden couples, or people in some kind of physical relationship?