Out of curiosity

My friend and her boyfriend broke up when she was 7 weeks pregnant,she's now 30 weeks and has been seeing someone new for a little bit now. Just curious if anyone thinks it is wrong to have sex with someone who isn't the father? Especially if they aren't even being safe!? I haven't expressed my concern because it's not really my business but I'm concerned for the safety of the child..she barely knows this man and he could have stds she doesn't know about and she doesn't seem to even care. Maybe I'm wrong. Idk.