The way I see it, websites like that are saying they’ll only do it without a condom. You want it real bad, so it’s tempting to try to bargain about it, or maybe just take it off for now - it’s just a little while, what’re the chances it goes wrong? - but we all know that the smart move is to keep it on or back out entirely. Reasonable partners, of which there are many, understand and cooperate. And ones that don’t aren’t the type of partner you want anyway.