Once you open that door, even just a tiny bit, the Devil will kick it open. He will influence you, He will tempt you, He will haunt you day and night.
It's not worth fighting a battle you cannot win. So give up. Quit. Surrender.
Go into a quiet place where you won't be disturbed. Preferably at night in the darkest place you can find. Pull your pants and underwear down to your ankles and get on your knees.
Now start pleasuring yourself. Rub your cock, or finger your pussy and start praying to Satan.
Beg Him to take you. Offer all you have: Your flesh, mind, will, spirit, and soul. Give them all over to Him.
As you CUM, beg Him to possess you for eternity.
You belong to HIM now. You're going to love it!