Another thing I would add to cougars words is never bring a girlfriend into your sons life until you know it’s serious, (having been dating for 6 months atleast was my rule before me being introduced to girlfriends children) because it’s not right to bring a succession of people into there life they grow to love and then lose.
Because after four or five relationships you might meet the one but by then your son does not not only not make the effort but may prove to hinder your relationship.
I know growing up with several so called step dads