<human>: I met this guy about 1.5 months ago online. He still would log onto his dating profile and check (~ 2 weeks in), and I began to notice. I didn't really mind that, but then I would notice him logging in as soon as we got home after hanging out. About 1 month in, I finally decided to ask him about it. He said he hadn't been on any dates and only looks online to see who is looking at him. Fair enough. 

Recently, (1.5 months in) I saw his phone receive a text, from a girl, saying "mwah!". I couldn't let that go, and I did some digging, wrong of me, I know, but and they do appear to be dating and meeting up for dates regularly.

We had a conversation about being exclusive (~1 month after we met) and he pretty much just said he wasn't ready for it, but that things were going well. I agreed that things are going well, and kind of decided I was maybe being too paranoid. He is still logging on to the dating website and messaged someone that I know so he is still keeping his options open. I feel like I am going crazy trying to figure out how many people he is seeing and where I rank in his harem. I can't tell if I have turned into the psycho stalker girl or if I am just intuitive and trying to protect myself. It's probably a mix of both, but something needs to change. 

Should I just end it? I know several friends who have been in situations like that and it turned out ok, but it feels awful on my end, despite how much I like him. We always have such a fun time together, and we have started to be there for each other for the not-so-pleasant times either. Should I just keep looking?

Also, if I am to end it, what do I tell him? Do I admit that I looked through his phone? Is 1.5 months still a reasonable time frame, or should he know by now?

Give me a shortened version of the text
<bot>: Have been dating a guy for 1.5 months that I really like, doesn't want to be bf/gf quite yet but swears he is dating only me, when he is actually dating a few girls.