the first time, for men?

Well me and my girlfriend are both going to loose our virginities together tomorrow. We talk about what we are gonna do whilst having and everything will be in a good mood. But I know that men quickly and she knows to, which shouldn't be much of a problem but I want to last longer, what do I do? Go for breaks between the first and second round? ALSO we are loosing it in the Viennese oyster position, any tips about that? Thanks in advance!!!