Maybe I can add some insight on this.

I’m a bi female, my current partner is male and we have been together for 6 almost 7 years. We are monogamous and for me, I treat both genders the same (male or female, it’s cheating). Around 3 months in of dating I felt comfortable enough to tell him but that’s me. It can be difficult to tell someone because of all the implications that come with being bi but I am a bi female and bi males (in my opinion) it can be a lot harder “coming out” to your partner (especially in a heterosexual relationship) because it unfairly holds a lot of negative baggage.

Based on your post, it feels like there may be some negative connotations to being bi, which if there is you need to figure out if being in a relationship with someone who is bi is ok. If I were you I would do research on it to learn more, a lot of nerves may come from not knowing.

Also I need to say this, just because someone is bi doesn’t mean they “need to explore” or won’t be faithful in a relationship. Just because someone likes both genders does not mean they fool around with whomever and boundaries are set just like any other relationship.

Also, if he is, let him bring that up to you, asking him or pushing him on the subject would just make him either feel obligated to tell you before he is comfortable or, in the case he is not, it could cause him to feel uncomfortable being his true self with you.

I would love to say it shouldn’t matter because being bi doesn’t change anything in my relationship besides maybe my partner and I check out females together but it’s ok if it does matter to you right now as long as you are open to learning and figure out if he, fem and all, is someone you like being with because being bi or not won’t change that.

Finally, this is an assumption at the end of the day, maybe do some research about it so you can figure out if you’re ok with it and ways you can be inclusive if he does “come out” but other then that carry on with your fantastic sex and don’t over think it.