Apparently this is the first really hot sex scene Will has done. Hard to believe, I know, but apparently true. The interviewer was shocked to hear that Will wanted Jada to be on the set and watching when the scene was shot - which Rosario says he kept putting off until the end of production.
Will says he was very nervous about being in bed with Rosario and her being naked. He didn't want to touch the wrong place or do the wrong thing, and there are all those production people looking on to add to the stress. Sounds like he didn't want rumours getting back to Jada, which seems strange since it's common knowledge that they have an open relationship, at least in theory. In fact, the following is a direct quote from Will:
'In our marriage vows, we didn't say "forsaking all others". We said, "You will never hear I did something afterwards". Because if that happens, the relationship is destroyed.'
Will's also been quoted in the past saying that they have an agreement that if they sexually desire someone, they talk about it and go from there. He has also said that Jada is the queen of his life, and that as along as she is happy and he doesn't do anything to hurt her or make her unhappy, then yes, sexual flings are an option.
At first his reluctance and nervousness on the set seems inconsistent with that admission, but I imagine the burden for public figures is much greater in terms of getting attention from the press about anything that remotely smells of infidelity. I can see why he'd not want any rumors to be flying about that might upset his and Jada's agreement and introduce doubt about their agreement to be transparent to each other when they fancy someone else.
Jada *was* on the set, and she told Will in front of Rosario and others that ...
...he was not to embarrass her (by wimping out) and that he "had to bring it ..."
That Jada is one cool lady! Rosario says there was lots of tongue, and that she could tell it was permitted, though Jada didn't say so specifically.
I hate to think that Hollywood actors actually have to negotiate every move with their realtime loves when they do love scenes with others, but jealousy knows no boundaries when left on its own to do what it will. But of course, most of the movie set sex scenes are carried out with somebody really hot, so I guess it makes sense that it has very real power to push buttons.