How do men who want to have sex without a condom plan to respond if the woman becomes pregnant?

Do they really have unprotected sex after thinking that far ahead? Isn’t wanting to do it without a condom without considering the consequences incredibly irresponsible? If I got pregnant and told him, I can’t help feeling he’d just run away saying, “You can’t prove it’s my child, can you?” Even if I were seeing multiple people and couldn’t determine who the father was, you still couldn’t prove that it wasn’t your child, could you? I’m a woman and I take the pill, but I don’t tell them that—I ask them to wear a condom. If I told them, I feel like they’d try to do it without one. It’s simply one way of protecting myself. The pill isn’t 100% effective at preventing pregnancy, and it doesn’t protect against STIs either.