I think along the same terms as your boyfriend, I guess. To me, my boyfriend posting naked pictures of himself online would an invitation to having cybersex with other guys, and I don’t want my boyfriend beating off to other guys. While other people have their opinions, cybersex and sexting is considered cheating to me, and there is no reason for you do so if I’m fulfilling your needs. If I’m not, talk to me about it and if it’s something you can’t come to terms with, leave me.
My personality is hard-wired to be attracted mentally and sexually to 1 person at a time, and I would rather breakup with somebody than to cheat on them.