Robert Pattinson claims he lies because he has ''heavy saliva''.

The 28-year-old actor admits he often tells fibs which often lead him into awkward situations but he blames his propensity to lie on the fact he has thick spittle in his mouth.

Asked about why he feels the need to utter untruths on US Chat show 'Jimmy Kimmel Live', he explained: ''It's panic.

''It's sometimes ... you know when you go down the rabbit hole of things you can't get out of.''

Before he added: ''I have extraordinary heavy saliva.''

Show host Kimmel asked: ''What does that mean?''

The 'Twilight' hunk replied: ''It's funny. I noticed it the other day.

The Hollywood star then questioned the conversation, saying: ''Why am I talking about it?''

Jimmy asked: ''You mean it's got more thickness?''

Prompting Pattinson to reply: ''It is. I try and spit I can only get it about a foot.''

A seemingly stunned Kimmel then exclaimed: ''Really? What?''

Pattinson then offered an explanation, saying: ''Someone informed me the other day it's because I have heavy saliva. I thought it was because I didn't have much lip power. I find it easier when I'm lying ... I think the panic and the adrenaline...''

Later in the interview the conversation took another odd turn when the actor - who was in a long-term relationship with his 'Twilight' co-star Kristen Stewart and has been linked to singer Katy Perry - joked about getting aroused by being spat on.

Pattinson asked the interviewer, ''Have you ever had someone spit on you in a erotic way?'' To which Kimmel replied: ''Let me think about it for a second ... No, no I haven't.''

The star then said: ''It's pretty great.''