Facebook messages

Brooke • I`m 27 & from Louisiana. Married to a wonderful man. one sweet baby girl & 2 fur babies
Just saw a message on Facebook from Friday.(I don't check messages very often obvs) It was from a girl saying she'd been messaging and talking to my husband. Said she didn't realize he was married. I don't know what to think or honestly how I feel right now. Just sort of numb.