Yes, it does come. But you have to work at it. Tell them what you want to achieve and it makes it easier.
I can often be heard saying "right that's a nice boring pose for grandma, now lets sex it up". A few giggles etc but then the b&g realise I'm serious about getting some proper, romantic, loving, amorous, intimate pictures. Basically - SEXY!
Get her to grab him, pull her towards him, hand on hips. Get him to push her back, moving in for the kiss. Play around with these poses and you'll find the ones you like. Again I can be heard saying "actually that looks crap, let's try……" Again it shows the b&g that you care enough to admit that the pose isn't quite what you want and that you'll rework it to get it perfect. All the time being conscious of the where/how the dress is lying, having good lighting and no distracting elements.
The good news is it comes with experience. It comes quicker if a) you care b) you look at other's work c) you practice d) you involve the couple from the outset.
HTH