Ben Stiller and Robin Williams in 'Night At The Museum'

Ben Stiller was disappointed his monkey co-star didn't have sex in 'Night at the Museum'.The comic actor joked he wanted the family film to be spiced up with some raunchy love scenes.Ben told E! online: "I wanted to have more sex in 'Night at the Museum' - I wanted to see that monkey get excited!"The 41-year-old actor loved the freedom of swearing in his new movie 'The Heartbreak Kid' and believes cursing should be common practice.He said: "I hadn't done an R-rated film since 'There's Something About Mary' in 1998, and I'd forgotten how freeing it was. You just censor yourself so much more in PG-13 films - you can only say the F-word twice - what kind of movie it that? "I want us to have to say the F-word more and more in life."Ben is planning to take a break from comedy films after he finishes shooting 'The Hardy Men' with Tom Cruise.A source close to the actor said: "Ben is well aware he is becoming known as a comedic actor, but he knows there is a whole other side to his acting that people haven't seen. He thinks if he does a couple of serious roles, he will be more respected as an actor."