Day Tripper - Lennon/McCartney

Quoted from Barry Miles' Many Years From Now:

p. 209: YESTERDAY was released in the USA as a single in September 1965 and went to number one. When the Beatles played The Ed Sullivan Show on 14th August live before a television audience of 73,000,000 people, Paul sang the song backed by a string quartet from the New York Ed Sullivan Orchestra. This was a period of increasing confidence for Paul and John as songwriters; a period of transition where they felt able to insert private references about sex and drugs into their songs, knowing that in many cases even George Martin would not catch on. A good example, one which combined both sex and drugs, was their next single, DAY TRIPPER, co-written in October 1965 at Kenwood.
PAUL: This was getting towards the psychedelic period when we were interested in winking to our friends and comrades in arms, putting in references that we knew our friends would get but that the Great British Public might not. So 'she's a big teaser' was 'she's a prick teaser'. The mums and dads didn't get it but the kids did. DAY TRIPPER was to do with tripping. Acid was coming in on the scene, and often we'd do these songs about 'the girl who thought she was it'. Mainly the impetus for that used to come from John; I think John met quite a few girls who thought they were it and he was a bit up in arms about that kind of thing. SHE SAID SHE SAID was another one. But this was just a tongue-in-cheek song about someone who was a day tripper, a Sunday painter, Sunday driver, somebody who was committed only in part to the idea. Whereas we saw ourselves as full-time trippers, fully committed drivers, she was just a day tripper. That was a co-written effort; we were both there making it all up but I would give John the main credit. Probably the idea came from John because he sang the lead, but it was a close thing. We both put a lot of work in on it. I remember with the prick teasers we thought, 'That'd be fun to put in'. That was one of the great things about collaborating, you could nudge-nudge, wink-wink a bit, whereas if you're sitting on your own, you might not put it in. You know, 'I'd love to turn you on', we literally looked at each other like, 'Oh, dare we do this?' It was a good moment, there was always good eye contact when we put those things in.