Wear a speedo then get something like this to help add some cushion. Some of the speedos I bike in are smaller than this insert.
But I've been able to tuck it in without any issues and still have a comfortable ride.
https://www.aliexpress.com/item/2255799900716545.html?spm=a2g0o.order_list.0.0.122 01802x6pK7w&gatewayAdapt=4itemAdapt