You're going to have a lot of physical contact
Before this relationship begins, you are just adult friends. You don't want to have any physical contact with your friends. However, as you make love more often, you get used to touching each other's bodies. So when you go to a party with your common friends, you unconsciously touch your partner's body. Maybe you don't care about the details, but it really shows that there are some subtle changes in your FWB relationship.
You may miss each other
Since you joined the FWB relationship, you may meet and have sex every few days. As time goes on, you may get used to this kind of life. However, when you haven't met for a long time, you may start to miss your sexual partner. It could be missing her body, or it could be missing her. Either way, it means you may have some emotional attachment to your partner.
The number of times you meet has increased
In fact, the best number of hookup finders to meet is once a week. This not only gives you enough space to explore sex freely, but also prevents you from starting to have emotional attachment to each other due to too long meeting time. So, when you find that the number of times you meet has increased, you should realize that this may be because your focus has changed. In other words, it's possible that you don't meet because you want to have sex with each other, or you miss each other's company.
You're together at the weekend
In a healthy FWB relationship, casual encounters only ask to meet their sexual partner when they want to have sex. And will leave at the end of sex. On weekends, we should all be with people who are important to us, such as our family and friends. So if you and your partner are still together on the weekend, it's a very unusual thing. This may indicate that you may have fallen in love with your friend.