Am I being jealous?

So my boyfriends in a club with 8 other girls and one guy. I've never met the other girls but I will be soon. They know he has a girlfriend. Is it weird that they text like everyday? Sometimes it's about the club and other times it's about school like homework. They sometimes text like at 11 pm too. I feel like if they had some respect for me they wouldn't be texting him so late or like everyday. Am I just over reacting? I don't want to tell him anything because he gets upset and feels like I accuse him of things or I'm being please:(