When do you know if there's chemistry?

By date 2. If there's no spark after two dates in normal conditions (not drunk, not stressed), chemistry probably isn't developing. Some people take 3-4 dates to relax, but if you're still not interested by date 4, let them go. Chemistry is real and detectable early.

When do you know if you're compatible?

By date 5-6 (about 3 weeks). You've had enough conversations to assess values alignment, communication style, and basic personality fit. Not enough to know if you can survive serious challenges together, but enough to know if you're in the same ballpark.

When should you commit to exclusivity?

Around 2-3 months, after you've assessed both compatibility and readiness. Before two months, it's still early-stage attachment hormones. After three months, if you're still uncertain whether you want exclusivity, that's meaningful data—you might not be that interested.