This is a situation I would usually ask FFG about, but I'm almost afraid to know what they'll answer, so I thought I would get opinions here first (and if you know the designers' official position on it, feel free to tell me--just break the news gently).
The Relationship Card entitled Members of the Book Club (LatT) enables one member of a partnership to use the same tome immediately after the other member of the partnership has used it, even if it has been exhausted or discarded. However, the card does not specify anything about what the partner not holding the Tome card has to do about satisfying the Movement Points requirement. Since, by definition, it will not be that player's turn during the Movement Phase, it has occurred to me that maybe the intent is not to require a Movement Points expenditure, just the passage of the Skill check. On the other hand, if Movement Points are required, it would raise questions such as whether a partner who has already taken their turn during that Movement Phase can even use this option, since they will no longer have Movement Points (likewise for a partner in an Other World). It might also require a partner whose Movement turn is yet to be executed to keep track of MPs already expended, a situation for which I can't think of a parallel with other game effects.
Since both of these options seem either extreme or cumbersome, I've adopted a compromise which basically assumes that the partner of the cardholder gets an additional Movement Phase on the house as a part of this feature. They must still supply MPs, but they may do that based on their current values, regardless of whether or not they have moved yet on that turn. The only restrictions are that if the non-cardholder uses an exhaustible item (e.g., Map, Motorcycle), to supply the points, it remains exhausted for the rest of the turn; and that no one in an Other World can use the ability, since they never have Movement Points.
Another issue with this ability is that of discarding. At first, I thought it made sense to have only a successful tome-reading attempt by the holder of the Tome trigger a discard; but then I realized that that method was open to abuse, since the holder of the Tome could keep making low-probability attempts to read it and failing them, in order to give their partner repeated uses of a discardable tome. Therefore, I now play that the first successful read by either partner (except,of course, for the other partner's attempt on that same turn) triggers the discard.
What does everyone else think?