is my bf being shady

So my bf keeps texting people and idk who they are but he always deletes them. I just noticed him texting a girl which she said "I haven't said yes" and he replied "haha but you never said no 😂" is this bad (idk what to think)? Also later down the line she said something along the lines of "does anyone know?" I only saw this by looking over his shoulder when I was sleeping.