I chose "I'm male - equally bad"
I choose this only because I feel they're both kind of the same in a way. If your partner is going to emotionally attach themselves to someone else, it pretty much tells you how replaceable you are. I have the tendency to try to believe that "I'm the one for her, she's the one for me." This makes me think that I'm irreplaceable, and finding out that I'm not comes as a shocker when the person I'm with decides that there's someone else who's better.
Physically, I find it a lot worse. I even feel bad if the person has been with someone prior to myself. I'm a really jealous person, and I hate that. Knowing that intimate affection or even just a kiss has been shared bugs me to no end. I get that the person is no longer with them, but it's just at the back of my mind (like Dante Hicks in Clerks when he finds out that his girlfriend blew 36 other guys). Either way, physically cheating means that they don't care enough to control themselves.
I've only cheated emotionally with...well, four girls that I was in a relationship with, then I broke up with them or they with me. My ex cheated on me physically and then lied to me that she didn't--my friend saw her. We didn't really "love" each other, so it didn't really hurt. It just made me realize that that was out there. My current girlfriend, I would never cheat on, and I doubt she'd cheat on me.