Dating with marriage in mind, how long do you give it before deciding it's not going anywhere?

I hooked up with a scientist visiting my work and he unfollowed me after he flew back home. No explanation. Concerned about my job. Should I ask him?

What is the worst response to "Are you cheating on me?"?

Men who cheated in a 'perfectly fine' relationship—why did it happen?

What is it about people from seemingly unrelated fields suddenly pivoting to become tech/startup founders?

If she’s gorgeous, seems to have it all together, and still single. What’s your theory?