Fwb w/ an ex

I dated & lost my virginity to this guy about 5 years ago the break up was awful but we recently started seeing each other on a fwb level. Everything was going great till our last hook up, we tried anal (he’s done it before it was my first time.) after wards I went to go get my homework & study guides & he fell asleep. While I was studying for my test he woke up & just stared at me, watched me fiddle with my pencil & phone. My mom always told me that if a guy can’t stop staring he’s got feelings. I really don’t wanna mess this up cause what we have is good, am I just overthinking it?