Probably the best advice is take it slow, make sure you're clean inside with water if required, plenty of work to open things up, before slowly going for the main event
@JamesENL I know, actually never really succeeded. In the few times I've tried, it hurt her before I was even one inch inside so I pulled out. (and it was all in the distant past...)
I've got a mate who goes even deeper..... I am comparatively vanilla
TO the point where I don't think he can actually have a fulfilling relationship with someone cause all his fetishes are so impossible and that seems all he is about
So the fetish involves generally fiction (often slash fiction) where men can get pregnant through the unprotected buttsecks, carry the baby to term, then give birth through the ass
@JamesENL well, the most extreme fetish I've ever heard about is scat, doubt there's something more extreme. (learned about it thanks for the famous two women one cup vid which made me look a bit before going silently away ;))