What happened to Jeffrey in the British TV sitcom coupling?

Question

I have watched season 1,2,3 and 4

Answer 1

There's a bit of a mystery surrounding Jeff's disappearance in season 4.  I'm a huge Coupling fan and I was so disappointed when I heard he wasn't going to be in the final season.  

Apparently when season 3 finished filming the actor who played Jeff still intended coming back for the fourth season.  But then sometime he must have changed his mind and decided not to.  Steven Moffat who wrote the show begged him to change his mind and come back but it didn't work.  I don't think even Steven Moffat knew the reason why he left the show.  That's why there was no "ending" for Jeff or a goodbye scene so it was written in at the last minute that Jeff had gone on holiday to Lesbos and they got that actor who played Oliver to replace him.  Season 4 just wasn't the same without Jeff though - he was my favourite character and it wasn't nearly as funny as the other seasons without him.

Answer 2

Really, he just sort of disappears after season 3.  In the season 4 opener, they show Steve on the phone, talking to Jeff, who is apparently on an airplane traveling to Lesbos, where he hopes to find lots of lesbians (of course!).

I guess the actor just didn't want to be part of the show anymore, but I don't know any more details than that.