Hyper Sexual

Since I've turned 40 I've been aroused and turned on by the simplest things. Im constantly aroused and constantly masterbating.
Im a mother of three. Average mother and wife next door type average looking 5 foot 6 and weigh 136.
My youngest son is 18 6 foot 200 pounds muscular handsome.
His father is in D.C with the army national gaurd.
I feel bad I've been walking around the house with a tiny egg vibrator in my pussy. It has a remote I've been using.
Twice niw Tyson my son has caught me masterbating.
Then over the last week Tyson has escalated things becoming flirty and grabbing me pulling me into his lap. Afew days of this and i let him fuck me.
He is good size 7 or 8 inches and thick. I've been teaching him how to eat pussy how to finger and how to fuck with out cumming in 60 seconds.
A week of this and he tells me today I've taught him so much he makes his girlfriend cum and he can last half an hour in her.
I feel so hurt and betrayal sets in i feel weird about it.
We have a talk and he plans on fucking me every chance he gets but it would be weird to other people if he and i acted overly intimate and he didn't try and nail every girl he went to high school with.
Right after the talk i picked out some lingerie and he fucked me for an hour straight