Preparing for fellatio will also present you with a good opportunity to determine sanitization issues. You would be permanently stretched after so many times. I assume you want to get through life without having your anus 'destroyed.' This means, first off, not having sex with guys that are well-endowed. Rule number two is choose your penises wisely. If he says he wont get tested, that either means he has had a lot of unprotected sex such that he is scared the results might come back positive or he's just not interested enough in you to go through that trouble (in which case there's no reason to be sleeping with him). As a newfound bottom, your top priority is to get through life without contracting a sexual virus. And while a lot don't, it's impossible to tell who does and who doesn't just from meeting and knowing a guy. The reality is a lot of gay and bi guys engage in unprotected sex like they were discussing the weather.