Husband secret chat

Hi , pls suggest , my husband these days started secret chatting with his colleague, I have full trust on him as he loves n cares me n my kid , n I know he was very reserved n he don’t cross the limits in his chat , but tht lady is married with 2kids n talking darling dear n miss u due to WFH like kind of messages .. they r chatting in emails I may look if accedentslly he thought but I hv seen few times , but day time they r chatting in office laptop messenger as I can’t see it .. he don’t know tht I have seen messages but I pretend like nothing I know, as I don’t want to argue or it may affect our relation I thought .. but no change in him am I worrying more or can I talk abt it with him , he says frnds .. so far he never had any frnds much very less but this lady I don’t what to say I too know her .. but am I worrying much 🙁 #advicepls