Tell Me What You Think About My Date Friday....?

I've been talking to this guy that I met on craigslist. He and I talked about a month online. Then on Friday the 13 (yes I know it should have been a warning) I went out with him. He is very sweet,polite, well mannered, and handsome. I had such a great time that I allowed him to take me out again satuday. We had an equally great time. We started talking about our friends, families, hobbies, etc. He told me that he really didn't have any friends. He had 2 girls that he met online that texted him. One texted him the first night we out. He texted her back and said he was on a date. She replied back "Why are you texting me then silly". That was the end of it. This past friday he and I went out again. We were gone about 5 minutes he recieved a text from a girl. Then he replied. During our lunch he received another text from her. It went on through the course of the evening to he texted her back 7 times. He and I was in a music store looking at CD's. I saw him texted her again. This time I saw what he replied. My date replied "Ok. You can tell me about it when you pick me up later". She was going to his house to pick him up. When we got back to his truck I asked him if he needed to go ahead and take me home for his other date. He wanted to know why I said that. Then kept telling me that she was a platonic friend. What is buggin me about it is the fact that he said they only texted. He didn't have any friends. I don't know nothing about her. Her name or anything else. I feel like he didn't tell her that he was with me. I think she is another girl that he is dating. I don't mind at this point. He and I are just dating. I mind the lies about it, What do you all think. Is there more to it than friends with this other girl? He and I are both adults. Our ages are 24&28. Thanks to all that give an opinion. I didn't go out with him last night. I felt he betrayed my trust.