anal for him

so my SO has brought up sticking toys in his butt, which is perfectly fine since i’ve been pushing him in that direction only cause we’re into so much & i want to try it (only when he’s ready or even wants to ofc) but my questions are, what are y’all’s experiences when it came to anal for him? things to avoid & things i should make sure to do? i would like to know how your partners reacted to it the first time so i know what i should expect & what he should expect :)