Girlfriend going out

Thought I’d make a quick post here. I’m mid twenties, girlfriend a couple years younger. Been together 4 years, have a baby together, unplanned.

I’ll jump straight to it, my gf is at a job party, I’m home with the sick child, no problems there. She said she’s probably gonna be a couple hours, then come home. Almost 4 hours later she calls and say the girls there wanted her so much to join them to city centre hitting either clubs or bars, not sure. I say I’m her bf not her boss and to do what she likes, so she’s going.

Thing is this gives me an unsettling feeling in my gut as in the 4 years we’ve been together she’s not gone out without me, we barely drink at all. My ex cheated on me on a night out so obviously this is assosiation anxiety, I see that.

So basically if she cheats I’ll probably never know, what can I best do to try and get that info without sounding like an insecure bitch? (which I am in this situation btw)