On dating websites, I see a huge red flag when a woman asks to move the conversation to WhatsApp: it means she wants to know my phone number.
You don’t know what someone might do with your phone number. She could send spam, sell it to someone else, or contact you under a different name to try to scam you. Having your number also lets someone call or text you directly. Scammers may use that access to make you believe they already know you.
By contrast, I see less risk in sharing an Instagram or Telegram username. You can easily change your Telegram username. If strangers know these usernames, you can block incoming messages from people you don’t know.
In other words, don’t give away your phone number to someone you don’t know.
