Rihanna and ASAP Rocky had fans thinking there was trouble between them at the Met Gala , but sources say that wasn't the case. A source connected to the stars tells TMZ that there was no relationship trouble, only exhaustion after an extremely long day. Sources said the couple had been going nonstop for nearly 16 hours, moving between preparation, appearances, and the main event, and were completely drained by the time they left. One source told the outlet, "It was a long day and they were running on empty." A viral video of the couple in a Sprinter van showed what looked like an emotional conversation. However, sources said the interaction was simply two tired people and not an argument or serious conflict. Another clip where Rihanna looked toward Rocky while he spoke with another woman, led fans to speculate about tension. TMZ reports that the woman seen speaking with Rocky is Giovanna Battaglia Engelbert, who has known Rihanna for years and has "a lot of respect" for her.…