If I wanted to watch a sex scene, I would just seek out soft porn. However, I don't want to watch a sex scene. I don't ever watch porn- don't care to watch it. However... the kissing, some kind of conversation maybe, and they disappear for a bit, then are shown in "after glow"... such as what Jason suggested- I like that. Let my imagination figure out what they did in the bedroom, I certainly don't need to see it on tv to get the idea.
And if I must see them in bed together... I don't want to see too much. Again- I have 2 children, I know how the hanky panky is done. Let my imagination have a little fun, my eyes can't unsee the images you come up with.