for us i think an hour has probably been the longest. though wonderful when we have it, our sex is generally the SHORTEST sex i've ever had with anyone. i once went SIX HOURS with a guy. it was a life-altering experience.
with other partners the most amazing times in bed have been probably close to 2 or 3 hour sessions. the build up, the foreplay, the fucking, the cuddling, the buildup, the fucking, the cuddling... the foreplay the... bonding.
i really enjoy our sex but i wish he wasnt so impatient. he's pretty young and inexperienced (im his 3rd partner) and i try to tell him to slow down but sex is still all too often just a mechanical process for him.
all the toys we get here help to open us up and keep his attention for longer.