Not sure why (General)

Steffy should certainly tell Finn. She needn´t be afraid that he would punch Liam, Finn is not violent.
But he would certainly tell him off.
Better than Finn finding out some other way and being mad at Steffy for hiding it.

But I wish Steffy would be upfront and honest with Finn and tell him what Liam has been doing. I think Finn should know the kind of friend Liam is

I’m not a Steffy fan but I feel the same. I guess I’m Td because Finn when he gets a chance is the most normal, dependable character on the show.

She probably doesn't want to disrupt the peace since they share child.

I agree though, she needs to tell Finn.

STEAM kiss will come back to bite them all.
Though Finn forgave sex & a paternity scandal with Liam so yeah he’ll forgive Steffy again.
The only way SINN implode will be Steffy’s doing if she starts on the STEAM path again . Surely not! You’d never forget lying on the ground while pregnant begging your husband not to leave…..

Why would she? She is one the biggest hypocrites on the show when it comes to cheating.

She only fesses up when she is caught.

But I wish Steffy would be upfront and honest with Finn and tell him what Liam has been doing. I think Finn should know the kind of friend Liam is

Exactly he should be punched out

But I wish Steffy would be upfront and honest with Finn and tell him what Liam has been doing. I think Finn should know the kind of friend Liam is

Me too, but I guess Steffy can't tell because the writers need Finn to be angry soon...

But I wish Steffy would be upfront and honest with Finn and tell him what Liam has been doing. I think Finn should know the kind of friend Liam is

I believe Steffy’s reasoning is that it will disrupt their peaceful existence for no reason. It meant nothing and she handled it so why make things uncomfortable between Liam and Finn when they have to coexist?

She is in a tough position.