Why Did Ann Margaret Kiss Roy Scheider After He Dispensed Wth Link?

Why did Ann Margaret's character kiss Roy Schneider's character after he kicked the stuffing out of Clarence Williams III?

It happened at their house after Harry Mitchell ran Bobby Shy off the property. Barbara had been hurt and pi**ed that he cheated on her. But she flipped back after that incident.

Why did she kiss him? Was it for the same reason that two years later Annette Bening's character kissed Warren Beatty's character at his house after Bugsy beat a man to death in the movie Busy?