My sons cup has mold

This is my sons favorite cup and I never knew to take the straw all the way out. I would take the bottom apart and wash in the dishwasher or by hand with hot water and soap. This is a Playtex cup. I decided since I've never taken the straw all the way out I should try too and that's when I found the mold. Seems like the mold is also in the straw itself which is hard to clean. Just want all the parents out there to check their kids cups and make sure no mold is on the straw. Since I took the straw out, it won't go back in which means I need to buy a new cup, I'm sad because that means other parents haven't done this and their kids could be getting sick off the black mold growing on the straw.