Probably do to the huge amount of adrenaline and other hormones in your body body right now, you actually over power the tentacles holding your arm in place. Moving your arms despite their attempts to pull you back, you grab the tentacle constricting your cock, and are even able to loosen it. When it gets loosened enough, you cock explodes in a way that is even more intense than what happened in the demons cave. It's incredibly intense, as all the pleasure that was being pent up for the few minutes when your cock was constricted is felt at once. You can see the cum being pumped out of your cock into the tentacle. Since the constricted tentacles suddenly becomes slack, is no longer trying to torture your cock. Instead, the cock tentacles begin rubbing/fucking your with renewed fury. You cum twice from the vaginal fucking before your cock is done ejaculating, and while your still in the midst of your last orgasm high, tentacle cocks reach their limit and begin to cum, the one in your mouth pumping the plant seed down your throat into your stomach, the one in your pussy filling your womb, the rest spraying your body. Before its over, you black out.
When you wake up, your still covered with cum, and Sam is lying beside you in similar straits. It reminds you eerily of the night after the demon cave. You wonder what do next, as it would be kind of embarrassing to walk into town covered in cum. The towns people would probably want an explanation. You could ask Sam if he knows a good place to clean up outside of town. You also consider that you could just leave now, and not even bother with the town. The succubus' offer is still echoing in the back of your mind though. You feel an odd rumbling in your abdominals and wonder if your body has changed as a result of the encounter...
Spoiler (click to show/hide):
Lust level 10
Sub level: 12
Dom Lev:14
Corrupt: 24
GM roll=6 Urta is pregnant with a plant creature birth within 10 turns or so, no exact count.