A tease for two...
If you can't find anything, a Q-Tip will work.
Now go very slowly if you've never done this before. Push it in and out just an inch or so a few times. See how he reacts. Put it back into him for an inch, and hold it there. Move it slightly without pulling it out and spit on where it meets his ass.
Do this a little at a time and go further and further. Go easy and don't rush it, let him focus on the sensations.
Fuck his ass as long as you like. After you get it going, ask him how he liked it. See how much more he wants. Ask him if he wants you to stop. If he says yes, keep going for at least a minute longer, even if its just barely touching him. Tell him that you are in control and not him.
If you can reach around and feel his cock. Keep him hard as you take your time.
When you are ready, continue.