I like reading stories, bl or otherwise, when both characters are well aware of sex and what that entails. Even if one character is a virgin, and might be nervous, they aren't naive about it. One bc im tired of reading those plot lines. But majbly because a lot of these smutty BLs dip into kinks and bdsmesque stufd and it always comes off a little weird when the majn character has never had sex before and their first time is some real kinky stuff. Like some of those characters gave never even masturbated before. when both characters have experience I feel like it translates better.