Imagine a scene, where you are being cajoled into accepting an invitation to breakfast, shopping, the movies. In these instances, there are often few dire consequences to either person if the invitation is rejected. Yet, when it comes to sex, everything changes. Everyone reacts slightly differently. What turns one person on, may turn the next person off.
People are all different.
In fact, what works one day, with the same person may fail the next day. However, even with all these unknowns, there is one helpful rule to keep in mind. Invitations are most likely accepted, when both people feel good about the relationship. This might mean engaging in a meaningful conversation. This is simple and direct.