Once you’re all the way in, give him a minute to adjust, and only start thrusting in and out after he’s given you the green light. Talk to your guy and ask him for permission as you’re going in. That’s the kind of behaviour that can put a guy off from getting f**ked for a long time, so, be incredibly gentle at first and work slowly together. It can really hurt when a top just sticks his cock in. Don’t just shove your cock in as if he’s a fleshlight (unless that’s what he likes and you’ve already talked about it).
When a bottom guy gives you his ass, he’s assuming you’re going to look after it. Being a top comes with a lot of responsibility