i need help for been a cuck

i need your help
Years now i try to convince my wife to cuck me
She always refuse. About two years ago i achieve a 3some with a friend of her.
He didnt actually fuck her but she j/o him she suck him and she let im finger her. She also let him to cum over her face.
Since then i ask her many time to do it again. She always refuse. Two days ago she told me that she had a dream about cheating me with some other guy. Last night when i was fuck her we take a position and she told me that its not possible to fuck her because my cock is small and its not possible to reach her pussy in this position.
Are those signs?
Any suggestions about how to convince her?
I also attach her pics to have more spherical opinion

small tits

full body

Try starting her out with a 9" dildo that will fit in her pussy just right . Lick and suck her clitty as you fuck her with the dildo . Make her have multiple orgasm's , eventually she may want the real thing .

Try starting her out with a 9" dildo that will fit in her pussy just right . Lick and suck her clitty as you fuck her with the dildo . Make her have multiple orgasm's , eventually she may want the real thing .

thanks guys
your opinions are totally different each form other but first i can try the skelley234 opinion.
Anyway my opinion is closer to nocturnalpermister. I notice those you describe at your post. I will keep try