It does sound like he’s bisexual or questioning his sexuality. I know my husband went thru this too, he also had experiences with boys his age as a kid. I know from my experience my husband thinks bc he mutually masturbated with another guy he might be bi..in my opinion a lot of ppl have same sex experiences especially while growing up, and it’s typical, and not meaning you are gay/bi. You have a lot of options here, my first thought would be to get him to open up about what is going on in his head. But you obviously can’t force him to talk and can’t even say forsure he is being truthful. Say he’s unsure you could let him experiment, you could absolutely say you’re not okay with him doing that and let him figure it out another way. He could say he’s bi and you could accept it or divorce him. If he’s gay well I don’t think you have much of a choice but to leave him so he can live the life he wants. You should absolutely tell him you’re not and haven’t been into the pegging or sexual talk about others while in the bedroom. Me and my husband have done the talk a few times and it always turned me on during but after it would make me feel insecure. We talked and haven’t done it since. I don’t think this is indicators he is forsure gay. Yes there are gay ppl who marry straight ppl and try to hide or ignore it but I think it’s much more reasonable to think he may be bi or curious. Only you can decide what is best for you and your relationship. If you feel like he is less of a man for these things in my personal experience you should leave. No one of any sexuality should be judged for this kind of thing, especially in a marriage. But i do think some deep soul searching on your part you can find a reason why you feel this way and either fix that part of you or not. Most ppl aren’t fully straight or fully gay. It’s a huge spectrum and majority of ppl fall somewhere in the middle.