Do guys normally keep their one-night-stand contacts?

I met a guy through an online dating app. We did had a nice time talking to each other but since I know he might just want to hook up with a girl when he was here (on a business trip) so I didn't expect anything. We slept with each other on the 3rd date and then he left. The problem is even I didn't expect anything from the beginning but after talking to him, I found so much things in common and the conversation that I had with him has been the most interesting and stimulating conversation that I have ever had with a guy. We had so much fun together talking about anything and everything, we even talked about our dating experiences and exes. The chemistry was there too (maybe just my side). I know that hooking up with girls anywhere he goes is a part of his routine so I didn't want to get emotional attached at all and didn't want to give him my number or any other option to keep in contact. However, the guy kept asking me for my number and email, he said that he did want to keep in touch with me and even he has to travel all the time, if I drop him a message, he will surely answer it. Also, he told me that if I happen to come to his town, give him a call and if he's there, we can meet each other gain. I wonder what he has in mind by telling me all those things. Also, is this normal for guys to keep in touch with their one-night-stand girls? I'm so confused right now because I really like that guy but don't want to be a fool expecting something will happen. Maybe he said so because he's a professional womanizer? Does he really like me too?