Stain in white Speedo

[singletlover]

I was sorting my collection the other day, since it is time to scale down the mountain (literally) of swimwear, underwear and workout wear. Sorry got away from me.

My bright white double layered Speedo has a stain on the front. Not sure where or what, or how long it has been there. The stain came from the front as the inside has no stain.

I need suggestions to carefully try to remove this light discoloration.

Thanks all