How long does your penis stay completely erect

[Lord_of_Goon]

7x5.5: Ok, ready for a somewhat hypothetical question?

Your girlfriend is out so you are watching a porno, and bring yourself to a complete hard on. You then turn off the porno, and cease any sort of contact with your dick (ie take your hand off). You also cease all sexual thoughts. How long until you lose your erection / your erection loses its angle?

Depends on my mood. But I always challenge myself and time limp to erect to limp to erect.