How do you tell your boyfriend he needs to clip his nails?

I just recently had my boyfriend, okay well guy friend that I got intimate with, over and he had really long fingernails. Well, not disgustingly long, just longer than I'm used to. I'm a nail-biter so I'm used to barely any nails at all and I just find longer nails really gross on guys. How do I tell him without sounding rude or ridiculous?