Unsure

This is so personal but I had to vent somewhere to someone. Curtis started a new job. YAH! He driving a dump truck. They have eight truck drivers, 2 are women. The 1st day he told me about both of them. Infact, one lives in the same town as us. He told me that she was pretty, not married (no ring, shit, I don't wear my ring sometimes) and he would like to fix her up with his brother. Hey cool.
Remember, this is just his first week on the job. They don't ride in the same truck, or work in the same little office space.
I found out yesterday they went to lunch together and he bought. What the hell? I worked in the mechial business for 3 years and never went to lunch with any of the guys, or let them buy me lunch. I was even single at the time. Many of times they asked me out after work to have drinks. Never!
He said, I am over reacting but it makes me feel so uneasy. I don't even know why he makes me feel this way. He has never done anything like this before. We are talking about my marriage here. The man I took vows with. We didn't even speak more last night. I was too upset.