[GTL]

i was in a similar situation this summer and ended up feeling [censored] about my lack of action as well. was walking down the street in Provincetown, Cape Cod which is a really small touristy type town. Lots of people on the streets and lots of drinking. A couple is having an argument and people are starting to pay attention. You can tell that the guy is about to hit the girl any second. I'm walking with 2 other guys, and if we had just moved toward them and spoke up we could have stopped him from hitting her. Instead I stopped and watched them fight some more before he finally slapped her. She fought back, slugged him a couple times in the face and he walked away.

Didn't call the cops, didn't stop it. Still feel [censored] about it because there was no chance of me getting my ass kicked. Was a crowded street and I had friends with me. Should have spoke up sooner.

In your case, there was nothing you could do. Calling the cops might be best, but it won't really change anything for either of them.