My characters help with these scenes. The more intense the character, the hotter the scene.
One of my current WIPS is actually a rewrite of a former story I wrote and published online about five years ago. I'm taking very little from the original, only minor plot elements, but the most important part that is staying in the story is my Hero.
Tex, as he has been reborn, is as intense as they get. He's consumed by Eden. Every part of him loves her. He craves her, has held on to memories of her and the way she made him fall in love with her for years. When they reconnect, the fireworks they'd ignited in their youth become full-out bombs. That kind of intensity is a blast to write. When his every thought, every action belongs to his girl, you know that once he gets to share that adoration with her, it's going to go off.
Tex takes intense to a whole different level. He will come off as obsessed, controlling... basically dyed in the wool Alpha barbarian, but at the heart of his behavior is love. He cares. Admires. Worships. Worries. Protects. Possesses. Loves. Everything about his character is full color. Red, red, red. He doesn't do wishy-washy. He's very driven, very determined and very ambitious. This carries on to every aspect of his life, but when it comes to Eden, he goes 110%.
Whenever I write a character like this, I almost welcome the "Caveman" comments. You're damn right he is. He's completely driven by testosterone, ego, pride and his heart. Personally, that's the kind of hero I like to read. The more they beat on their chest, the squishier my heart gets. Drag me to the bedroom by my hair. Catch me if you can. Show me. All I can say to the gals that tsk-tsk the knuckle-draggers... they obviously haven't been thrown over the right man's back and been carried off to be devoured. Sorry about that, ladies. You're missing out.