This is a bit much. It’s one thing for your husband’s friend to cheat on his wife. That’s his choice but to have your husband basically aid him is not cool.
Birds of a feather flock together. You can have friends who do questionable things often times if they know you are going to be the morality police they may tell you but not involve you. That’s how my friends roll. They also know since I’m going to call them out on their mess they ask me if certain things done in my presence would be offensive. Sounds like your husband’s morality line is wide enough to be accepting of his friend’s ways. If your husband’s friend knew that your husband was cool with it it’s no wonder that this invite wasn’t an issue.
The other flip is that your husband isn’t aware of your morality line. I’m team wife all the way. My husband knows I will call him and his friend out so no need to even involve me. Even if there’s a wife that I don’t particularly like I’m still team wife. Ain’t no way in Hell we breaking bread with active cheating. I’m loyal to my husband but the loyalty goes both ways he wouldn’t betray me knowing how I feel about certain things. Your husband has very little respect. Any man reading this and thinking “well my wife should be good since I’m good” is pure trash. I would imagine if we set up a sting you doing questionable stuff towards your wife too!
I believe your friend has a right to cheat meaning I don’t condone it but it’s his choice. However I’m pissed as all get out that he would be that open. This is not I made a mistake with another woman this is a whole mistress aka a side relationship. Just the amount of diseases (condoms don’t cover everything) he is potentially bringing home is enough for me to cut him! Yes I said cut him.
I would say you tell your husband that you’re not comfortable with it and that you decline the invitation and have a conversation with him about his participation. Something about this makes me leery about his own morality and you need to see this as an immediate red flag!
There no way to involve other folks without their knowledge and I wouldn’t want to be uncomfortable. Men if you cheat than either be bold enough to speak up and if you can’t the less you involve others the longer it allows you to be secretive until you get caught because 9 times out of 10 you’re going to get caught. This is 2019 somebody is recording, snapping, and setting you up in case you think they aren’t! Don’t be dumb!