IHTM14339 - Lifetime transfers: gifts with reservation (GWRs): the reservation: benefit to donor's spouse or civil partner
Except as in relation to insurance policies (IHTM14421), the gift with reservation (GWR) provisions do not extend to gifts under which a benefit is reserved to the donor’s spouse or civil partner (IHTM11032).
However, if enjoyment of a gift by the spouse or civil partner is shared by the donor the GWR provisions will apply. As is mentioned at (IHTM14338), you may need to consider the associated operations provisions (IHTM14821) in this context.