Write a love scene between characters of your choice. You can decide how much sexual content you want since no one will read it but you.
1. No graphic sexual description. i.e. no blow by blow details. Make it romantic and sexy without drawing a picture. Behavior, dialogue, scene can create sexual tension without explicit details. It is a given that grown ups will read it and most of us know the "drill".
2. Use any POV you choose but you may find it easier if you do 1st person.
3. Yeah, it's difficult. That's the point.