Robert Pattinson and Kristen Stewart's love scenes were filmed on a closed set.

'This was the most mature film,' David said.

'We really wanted to address the sex issue, as we didn't want Edward to come across as a prude. But Eclipse does suggest that perhaps there can be a natural rhythm to a relationship and you don't have to jump into it straight away,' he addedd.

Telling all on how they filmed the heat-filled scenes, David revealed he closed the set, to create added tension between rumoured couple Kristen and Rob.

'This stuff is always awkward to shoot, and you just have to get people really comfortable with each other,' he said.

'We do it as a closed set. There's no giggling and joking around, and everybody treats it very professionally - that's just the way it works.'

And funnily enough, Rob and Kristen didn't have any trouble with the steamy kissing scene.

'They didn't seem to be nervous, they were to be fine with each other,' David revealed.

'We shot that on the very last night and it just seemed to go wonderfully. It just flowed beautifully.'

Letting on he thinks the key to the Saga's success is love, the Eclipse director added: 'To find something which is so unapologetically a true love story is so rare. The film wears its heart on its sleeve. I think it's culturally quite healthy to see true love as a nice thing, and not to get all angsty.'

Source via KstewRobFans