After making up my list I found that not only are these films completely clear of sex and nudity, they're also really clean in every other department! (and no less enjoyable for it!)
1. Cinderella (2015 live Disney version)
This is likely the best take on the classic fairy tale. It is a stunning romantic drama with good character development. Very clean and very much recommended!
About a failing marriage, Fireproof hits some pretty heavy topics, but you'll never see anything inappropriate. The movie focuses around a man on the edge of divorce who receives a book called The Love Dare from his father. He tries to follow it day by day to win back his wife.
3. The Matchbreaker
This romantic comedy is about a guy who actually gets hired to break up couples, but ends up running into his childhood crush along the way. It's a great choice for just about any couple to watch!
Hope this helps with your romantic movie watching!