I first realized that I was bisexual when I allowed my younger brother to insert his erect penis into my rectum and fuck me until he came in me and pumped his seed deep into my willing body where I wanted it in there and that it belonged in there.
I want a younger guy to be my master. I'd submit to (most, depending) of his desires and fantasies. Would be great if he had a friend to join in sometimes, or even a daddy.
Of course you're going to cum inside. The whole idea of anal sex with another man is that you're going to enjoy the feeling of cumming in his ass and he'll enjoy the feeling of you pumping your seed deep into his willing submissive body where he desperately wants it.