Online - How much you want to engage is up to you.
- If you want to ignore it, ignore it.
- If you want to challenge them, then do so politely and with sound arguments.
- If they are really nasty, block them.
IRL - That depends on who is doing the forcing.
- If it is a person (such as a parent) on whom you are financially dependent, or a member of your family with whom you want to remain close, you might have to pretend until such time that you can make your feelings known.
- If they are a friend or family member whom you do not need to maintain a relationship, politely tell them you are not interested. If they persist, tell them they are not respecting your wishes. If the continue to persist, cut contact with them.
- If they are a stranger, laugh at them and walk away.