I usually average 15 minutes daty in a session, but have gone as long as 30 minutes. it depends on the provider really, because I can go as long as she will let me.
Kept going down on this lady throughout the night. We'd kiss, fuck, eat one another, climax and start again. It started about midnight and continued until I left the next morning around 11am. Longest continuouis DATY was probably around an hour..breaks to let her calm down, rim her or slip various objects in her pussy and/or ass. Finally she got so frustrated at being denied an orgasm that she pulled my face up by the hair and told me to let her cum or she was going to "make me pay" for getting her so wound up. It is great getting a woman right to the edge and then stopping...over and over..listening to her frustrated gasps and cussing before diving back in.