In the final two “Harry Potter” movies, among the foes battled by Daniel Radcliffe’s teen wizard was Bellatrix Lestrange, played by Helena Bonham Carter.

And while Carter’s character was Harry Potter’s sworn enemy, behind the camera the reality was far more complicated, as Radcliffe reveals in the upcoming TV special “Harry Potter 20th Anniversary: Return to Hogwarts”.

According to Radcliffe, now 32, he had a huge crush on Carter, 55, despite their 23-year age difference.

READ MORE: Daniel Radcliffe Admits He Was ‘Devastated’ Over Producers’ Demand To Maintain Harry Potter’s Shaggy Haircut 

In the special, Radcliffe reads a love letter he sent to Carter after completing filming on the final “Harry Potter” film.”Dear HBC, it was a pleasure being your co-star and coaster in the fact I always ended up holding your coffee,” Radcliffe reads aloud.

“I do love you and I wish I’d just been born 10 years earlier so I might’ve been in with a chance,” he continues.

That wasn’t the only crushing going on behind the scenes at the franchise. Emma Watson, who played Hermione Granger, reveals in the special that she had a crush on co-star Tom Felton, who portrayed Draco Malfoy.

READ MORE: Emma Watson Remembers The Moment She ‘Fell In Love’ With ‘Harry Potter’ Co-Star Tom Felton

“I walked into the room where we were having tutoring. The assignment that had been given was to draw what you thought God looked like, and Tom had drawn a girl with a backward cap on a skateboard,” Watson recalls.

“And I just don’t know how to say it — I just fell in love with him,” she adds. “I used to come in every day and look for his number on the call sheet, it was number seven, and if his name was on the call sheet, it was an extra exciting day.”