Although it is considered taboo, let me tell you from my own experience that nothing else can give you more pleasure and ecstacy than sex between mom and son. This is because of the affection and deep love between a mom and son which is not there even between married couples.
Those precious moments when your penis moves up and down in her 'love tunnel' is the most pleasurable moments for both of you and both of you will never derive this much pleasure and ecstacy from any other partner. So since you both have touched each other's intimate parts, you may now proceed to suck her boobs, which she will allow you with affection.
If there is any hesitation, tell her you want to play like a child with her boobs and you strongly believe that a mom's affection and love is filled in her boobs and you want to suck her affection into your heart through your mouth. She will definitely allow.
After a few nights of boob sucking alone, you slowly insert your hand into her panties and let your finger search for her clitoris. Stimulate her clitoris while sucking her boobs with your fingers and go down with your tongue and give her a lick on her clitoris with your tongue.
Suck it in with your lips and rub the clitoris with the tip of your tongue. Gradually go into full sex....... and experience what I have experienced many times. Never make her pregnant.
Me, at the age of 14 started experiencing this with my mother who was then 34. We continued it till she attained the age of 73. After my marriage even, we continued doing it . We both never had that much pleasure from our spouses. (She became a widow by the age of 29).
Best wishes ..... and please let us know the result.