It looks like Ben Affleck didn't have the best time at Sunday's Grammy Awards. [But before you read too much into that, a source told Entertainment Tonight about a very understandable reason why Affleck may have seemed a little less than enthusiastic that night.

"Jen and Ben had a fun date night at the Grammys, but they were both very busy working on several projects and Ben was feeling tired," the source explained.

"He wanted to go support Jen, but he wasn't his usual self."

Affleck's lack of enthusiasm may have caused a bit of tension with Jennifer Lopez, but sources say that Lopez was very understanding of why Affleck was not at 100%.

"Jen had a great time and wanted Ben to be excited to be there, but she understood where he was coming from."

The source also said that Lopez "knows how supportive Ben is of her and her work, but also understands that Ben is more of a family man and being at events all the time is not his thing."

"Whether he is out or relaxing at home Whether it's when she is out or relaxing at home, she appreciates his support."

"She is very grateful for the support he gives her.

These comments are consistent with revelations from a seating attendant who sat at the couple's table during part of the evening.

She said, "They were so lovey-dovey, always intertwining their hands, I don't know how to describe it, but they just were. So it was cute, not like, 'Oh, this is going to lead to divorce.'"

Cute, cute, cute.