I wear other various thongs as well, if they’re not crotchless I tend to just pull them to the side but after a while the string rubs against my ass cheeks- not fun!
I always wear backless knickers for pegging or impact play as I wear a silicone gaff (fake vagina) 24/7 so the front panel retains the gaff while my wife has full access for pegging or caning etc.
Only once did I wear a tiny men’s g string. She was about to take me from behind then pulled it to one side and fucked me hard. I came in the front pouch. It made a big mess. I like to be taken from behind naked so the cum slowly drips from my cock, building up so it is dripping constantly before I cum hard with a retracted soft cock.