Should I Take the Plunge?

So i'm seeing this guy, i've been seeing him for a little over 3 months now. Things got pretty serious pretty fast. We had both moved to a different state to better our lives, met up shortly after I moved down and hit it off immediately. He had been here for about 3 months before I got here. And in that time he had a girlfriend of 2 months. So the other night it phone indicates that he has a text ( I know cause we coincidentally have the same phone ). He doesn't check it immediately, instead he waits about an hour and then takes his phone into the bathroom with him. When he comes out I asked him if he always checks his messages on the bowl. Knowing that I was very curious, he explained the situation. Apparently his ex of 2 months, has randomly contacted him out of the blue (so he says) and is threatening suicide and sending him emails and text messages about how depressed she is after he left her. He showed me his phone but not the actual messages, the most recent started with "i'm home now if u...." he said that is because she wants him to call her. Now... He left her sighting "things aren't working out" even though he really left her after having met me. Two things that he said that night are burned in my memory: 1. "i don't pry into your personal life like this" and 2. "i took it in the bathroom because what if it was a dirty sexual message, I don't know what this girl is gonna do... And then you'd flip out like you're doing now". My respective responses were, 1. I don't have anything to hide and i'm not acting shady checking messages in the bathroom and 2. Are you expecting dirty sexual messages?? At one point I got really mad and I insisted that he tell her to **** off. He said I was being inconsiderate and that he didn't want a suicide on his conscience. Admittedly, that was pretty inconsiderate of me to say seeing as how I have experience a suicide first hand and it is very serious and very painful for all involved. So then she should seek out professional help, having her "first real boyfriend" (she told him, we are 26...C'mon!) back is not going to solve her mental health issues. On a side note: he also confessed a few weeks before this incident that he has cheated in the past, but has given up his "old ways" for me. Something that I cannot get mad at, because I too have cheated in the past and I believe that I would be faithful to him for as long as we are together. He says he told him this because he wanted me to realize how much I meant to him, but it just made me nauseous, nervous and a little insecure. My problem is, do I take the risk? Besides this one text message incident, he has been the most perfect companion any girl could ask for. He is a gentleman, smart, funny, affectionate, respectful..... Everything you could ask for in a guy, he has. I don't want to be a psycho girlfriend, i'm scared to bring up the text message thing again because it will make me look psycho, I will not snoop through his private things.... So do I just put it behind me and move forward? Does he really not see through her pathetic attempt to trick him back into her life? It's hard because i've been the girl that a guy has cheated with on his girlfriend of many years, i'm not proud of that, I was a little blinded by infatuation. But it made me realize just how easy it is to get a guy to stray. And I didn't even have to pull the depression card. I would never use that. Why do girls put on an act like that? And why do guys fall for it so easily? Lots of questions... Think about it, discuss...Relay some advice back to me. Thanks!