I want to convince him

So long sorry short my boys of a decade has brought up watching me get fucked by another man. He's very confusing because he's never said anything remotely like that before. He also seems super into it sometimes but others not so much. How do I know if he is serious? And how do I convince him to make it reality?
I can help you train hubby to be ready and willing to be a cuckold and beg you to fuck other cocks and beg you to let him lick your pussy clean. - robbiewillsucku@gmail.com
 
Each relationship is different. We all know there is a double standard for female sexuality, so if you agree too quickly you could damage what you have. Make him do most of the talking, he needs to sell you on the idea. Once the reasons are HIS reasons he will hold them tighter and defend them. Maybe you can agree to follow thru only for his pleasure: "Honey, I'll do anything to make you happy".
Tell him it's his fantasy so he makes all the choices, he has to "give" you to the other man.
This might give you some cover if he decides he can't take it IRL.
I hope you give some updates if things progress.
 
Post your nude pictures here and show him. If he can't handle letting unknown strangers seeing you naked, he probably won't be able to handle seeing you have sex with other men.