I would agree, but if Nat goes back to the frat house alone to meet Matt she would most likely end up way in over her head and in a world of trouble. Matt and his frat buddies are not like the guys she meets though Jenna. They are young and very overly cocky, they only care about what they want and what they get out of it, they don't care about the female regardless who she is.Ethan & Nat followed the invitation from Carl. In these scenarios (update 0.95) they don't know Matt yet as she was dressed with halter bodycon dress while on club visit earlier in the game. Their romantic and faithful level is high enough to not engage in any action without notifying the partner.
And they would do anything to use a woman like Nat all night long including getting her drunk and/or drugging her, they already
admitted to having drugs there. And Jenna wouldn't be there to help protect her by keeping Matt and his buddies under control.