It sounds like the best of both worlds so to speak, and what a fun and spontaneous way for it to happen!
The Mr and I have talked alot about wanting to have friends with this kind of a relationship. Great friends that we like to do things with from just dinner or a cookout at home to going to movies, shopping, games, trips, etc., then the added perk of occasional play when the opportunity presents itself.
If everyone was okay enough the next day to go to the movie and just talk about that and everyday things with no weirdness then I say just go with it and enjoy the new additional benefits of the friendship. facelick
Good luck and have fun.
Mrs Spoomonkey