I don't know really what advice I can give other than my own experience with having a male. At the time we were babysitting my boyfriend's mom's yorkie, so it could have just been a territorial thing. We had also just moved to a new apartment, so it could have also been because everything was unfamiliar to him. Anyway, everytime I saw him sniffing around, or if he even looked like he was about to start marking, I'd distract him by calling his name or with noise by shaking a soda can and then I'd take him outside. I've never used belly bands or diapers. Now he doesn't mark the house at all--he does it all outside.
I personally love having a boy (I've always had male pets), and it was not until recently that I got a girl. They are great together! If you do decide to get the boy, I think you'd be very happy!
