"Day trippers are people who go on a day trip, right? Usually on a ferryboat or something. But it was kind of - you know, 'you're just a weekend hippie'. Get it?"
A rake (or, by extension, a day tripper) is someone who leads someone else on romantically, without actually following through with a serious relationship.
The term "day tripper" was coined by The Beatles.
She was a day tripper, one way ticket yeah. It took me soooo long, to find out, but I found out.