Seems your wife has told her sister that you have a small cock and that is does not satisfy the way she likes. The cat is out of the bag so to speak. If you really love her, you have to let her have some big cock or normal size cock. She still loves you and has figured out the difference between sex and love. Now it is your turn to figure it out. She has had sex with the guy and loved it but she does not love him, she came back to your bed? So looks like you must decide if you can seperate sex and love. My wife has been fucking and sucking other men for over 40 years and even before we married. She married me, comes to bed with me and always gets me off whether she gets off or not. She does that through others that she uses for sex, not love. We have had a great relationship and she has taught me how to clean her after her bull unloads in her, how to suck them hard and put it in her and how to take a cock up the ass. She has brought many women home and after they have eaten and dildo fucked each other she lets me clean them. She is just a great wife, mother and total ***** for cocks and pussy.