"You shouldn't get an erection, mom..." My mom was wet even as she was brushing herself off, so... 4 hours
They are usually a normal parent and child. She likes to drink, and her mother enjoys having drinks on her days off from her part-time job, but she has a bad habit of drinking, and when she gets drunk, she doesn't care about anyone's body. It's related to the target. Maybe it's because of the alcohol, but my girlfriend's mom looks sexy today, and her tipsy son doesn't look half-drunk either...
