OH no do not ram it in
or he may scream and turn around and thump you!
no, it is best in my experience to use a covered finger first to gently relax his bum
and use your judgement as to whether he is physically ready for something slightly
larger. If so then a slim anal plug or the slim end of anal beads, gently going in further
as the beads get thicker and thicker.
After this is pleasing him then move on to the strap on. If the strap on is not too huge
(my own is the size of an average cock, around 6inches and medium thickness) but the
most vital thing is to very gradually insert the end and then slowly move in and out until
he can take more and more.
The man is the only person who can really tell you what is the best way for him. I find the
tricky part is getting the right angle for penetration. Trial and error is the way to get it right.
An alternative way is to lie on your back and let him lower himself onto the strap on. He is then
in control of the speed and how much he takes.
Having said all of the above, I have met guys who just want to be invaded! They come to me
already opened up and waiting to be vigorously done!