Could you explain the meaning of "it lasts in love"? I don't get the meaning well.
This is an interesting, unusual grammar construction. The more common, natural way to express this would be "sometimes love lasts." Instead, Adele has chosen to say "sometimes it lasts in love." This is not grammatically incorrect, but it is a bit unusual. It is probably Adele's personal decision to express her feelings in this way specifically. You can understand this phrase to mean, "sometimes love lasts."