Keep it spicy 🌶 or too much risk?

My husband and I are celebrating 10 years together this month and we are pregnant with our first baby! We are so excited and happy! Over the years I’ve kept things fresh by role playing, lingerie, porn, and trying to get good at oral lol. Believe it or not but my husband is the only person I’ve gone down on! Anyway, just a few weeks ago during a night he was very tipsy he mentioned allowing his best friend of 20 years in the bedroom with us . I’ve personally been friends with his bestie for the 10 years we have been together and he spends the night often when he comes over to drink with my husband. He’s a single guy, decent looking. Well my dilemma is I 100% am a religious person and I do not believe in things like this, BUT I strongly STRONGLY Believe that every marriage is different and if something works for your marriage then you should do it as long as it keeps both husband and wife happy. I told him I was hesitant about opening the can of worms and what it might lead to. But being pregnant has made me feel so not sexy , and we are down to sex only once a week now if that . My husband says he feels I’m really good in bed and wants to show me off, he even mentioned his friend could just watch us if that’s what I was comfortable with. He also mentioned in pregnant already so there’s no risk of getting pregnant by someone else lmao . I highly value my marriage and don’t want to do anything to ruin it but I’m open to the idea of it for some odd reason. After our convo my husband and I had really good sex and I was so wet just fro the conversation of bringing someone else in 😳 I couldn’t believe it myself . I’m worried I will feel like it’s wrong while I’m cooking my sweet baby to let someone else see me naked or worse insert himself inside me. This convo was 3 weeks ago with my husband and nothing came of it because I said I wasn’t sure yet, but I find myself imagining it actually happening very often and thinking about it. I’ve obviously not been with anyone else in 10 years and I’m actually not opposed to the idea but I thought this would come up later in life when Our kids were grown and we are in our 50s not now in our 30s lol but I guess that’s what happens when you wait so long to have kids. What would you do? I honestly dont think I could ever go through with it especially his best friend who we see all the time . Just curious what other people thoughts are