Wet patches ...

Ok this is going to be a rather odd question.. but I need some advice. I’ve noticed if I’m sitting down mainly on a plastic or so chair an then when I get up there’s a wet patch running along the chair.. I’ve googled and apparently it’s normal yet every time I’m sitting with a group I’m the only chair that has it and it’s sooo embarrassing. I even try to scoop my ass as I get up to wipe it but it’s still there ! Any tips ?? And is it sweat or discharge cos even I will be freezing cold and it will appear ?? Thanks in advance girls