Help them pick out clothes
Sometimes picking out your partner's clothes can be a really fun activity for the both of you. You can walk from store to store, learn what kind of style each of you like, and grow together by showing each other what you like to see on them.
Pick up a healthy snack like a smoothie in between shops, and just have fun! Try on things you might never otherwise try on to switch things up! You'll either be amazed by how sexy the other one looks, or both have a good laugh - which is sometimes just as good!