It sounds like one of the partners is unwilling to be affectionate even after the first one shows his/her appreciation. However, if the "Gift Giver" is only giving the gift to get sex ... that's not a good arrangement.

Now if giver of the gift likes to have sex and the receiver is rationing out affection ... why should the giver stick around if he (or she) is in a one-sided relationship?? In a nutshell, if the receiver of the gift CAN satisfy the giver with sex ... then the receiver should show his (or her) appreciation.