i am a bottom....due to the anatomy that remains after my castration...and by my desires. However, i think can add a bit. I had a lot of poz guys during my chase....and continue to enjoy poz on poz sex now that I have converted. Most of the guys who topped me while I was chasing were pretty clear of their reasons for being gifters.
Most simply understood the bond...and if you will...brotherhood among poz guys. They saw it as their role (maybe duty?) to help others who shared the desire and would share their situation after conversion.
Some, no doubt, simply wanted the "high" from spreading their toxic jizz. Those guys were mostly just a "hit an run" and simply wanted to notch another neg conversation.....good sex..but not much of a connection.
The guy who pozzed me was stealthing...(even though I was chasing...he still lied). He eventually came to tell me...but I was already converting by that time. His desire was to share his seed...I was his "first" willing partner...and he had not figured out how to really be up front about it. We eventually developed a real connection and still get together from time to time.
Now that I am poz, I understand the idea of passing along the bug. Since i cannot top, I have few choices. I have, however, induced lactation and am allowing a neg, twink to suckle my infected breast milk....very odd...and very strange...but it is a really nice connection with the guy....he has really thought out what he wants......most likely will not work...but it is very sensual trying.....