It wasn't an ugly spat. There was no screaming or hysterics involved but it was very obvious to everyone present that the lovers were having a tiff.
A source says, "Bebo and Saif walked in together. She wasn't her usual perky self. She was moody and withdrawn. The couple kept to themselves in a corner, and were arguing about something. The situation took a turn for the worse after Bebo put on a buddy-buddy show with Salman Khan (soon after Katrina's exit from the party at 2.30am). Kareena and Karisma have always been extremely fond of him. Bebo went across the room to greet Sallu, and this irritated her Nawab beau.
Adds a source close to the couple, "Saif is a very possessive guy. He doesn't approve of Kareena's display of affection for other male actors. Also, there were lots of big stars at the party (Salman, SRK) and in a situation like that, Saif gets really insecure. It was very obvious that he was getting irritated with Bebo's interaction with the other macho men around."
The source continues, "It doesn't help that Saif doesn't have too many friends in the industry, while Bebo is friends with most actors."
According to an actress present at the party, Bebo is normally restrained around her new beau but that day she was in 'high spirits' and was holding Salman's hand while talking to him. At one point, she even cupped Sallu's face into her hands.
Saif was sitting across the room and watching this drama. The source continues, "Bebo kept ignoring Saif and chatting with Salman. When she finally went back to Saif's side, he ignored her. He refused to speak to her and was sulking. She kept asking him what was wrong and why he wasn't talking to her."
At some point in the night, the actress began to feel sick, and Saif took her home, but he didn't speak to her for two days after that and even ignored all her calls and SMSes.
Saif chose to brush off the incident with, "The story is complete rubbish! Salman is my brother and the party was great fun." Kareena remained unavailable for comment but a source close to her states, "It's not true. Bebo didn't speak to Salman at all. She bumped into Salman on her way out with Saif."