Jesse Eisenberg used to write sex jokes on napkins when he was 13 years old.

The 'Double' actor - who is dating actress Mia Wasikowska - thought the gags were great at the time but admits he recently found it funny looking back on them because they are so ''misguided''.

He said: ''[I wrote] a lot of jokes, in fact. And they were all sex-based. I've since revisited them, and looking at them I felt like, 'Clearly, this person will never have sex.' They were just totally misguided.''

But the 30-year-old star later realised he wanted to write comedy movies after watching films by Ben Stiller and Adam Sandler.

Speaking about his thoughts after watching some of their movies, he added: ''I could write stuff like this.''

As well as writing, Jesse has gone on to land the part of Lex Luthor in the hotly-anticipated 'Batman v Superman: Dawn of Justice', and he he is enjoying the chance to appear in a big budget film because he is getting more of a chance to experiment with his character.

He told The Times newspaper: ''In some ways the Batman movie allows me to experiment more with my character because there's a lot more time; in independent movies I can sometimes only do one take of a very interesting scene, but in 'Batman' I can do 40 takes of the one scene just because they plan to spend the whole day on the scene because they have so much money.''