My baby is 6 months in 2 weeks. He stayed the night and mil and sil house last night. He came back with tea stains over his bib and sock. My eldest son then told me that sil had given him some of her tea to drink. Mil, sil and my partner are all denying this and claims the baby spilled her tea on accident and that’s how it’s over his bib and sock. If they did can this be harmful at his age I am worried?