That is a good question BR.
Thanks for asking.
I generally use the pullout method for two reasons. Firstly to impress them with my quantity that i estimate to be very close to a full liter. And secondly, they get scared of falling pregnant and usually like to go straight down to thepharmacy to get on the pill.
Very rare Thai females ask to use condoms these days. They are usually too shy to say it the first time so you just push through ok.
As Big Bird said, it reduces the pleasure.
Back in the 90s they more often did insist on condoms.
Other changes since then compared to nowadays I have noticed is back in the 90s not many were shaved, now it seems many are, or are willing to after a bit of hair pulling and teasing. Usually if you throw in the "monkey" word it motivates them.
And you would never find a three holer back in the 90s, the mere suggestion of it would get an "i am not a Ladyboy" reaction. These days more are willing to try it, but still less than 25% of them. They just need a bit of persuasion.