The partner who needs money

An attentive match professes strong feelings quickly, pushes to move off the dating app, and avoids real video calls. Then comes a crisis — a medical bill, stuck overseas, a customs fee — or a "can't-miss" investment.

What to do: keep chatting on the app, insist on a live video call early, and reverse-image-search their photos. Never send money or invest for someone you haven't met in person.