No hunni, he wasn't sincere. If he was sincere he wouldn't have asked you to spend the night with him when you don't know him. He was pretending to be sincere so you'd think he was ok.
My hubby once told me not to believe a single word a man says (until he's proved you can trust him) because the chances are that the majority are 'only trying to get into your knickers'. It's a wide statement that isn't true, of course, but his point was that women need to protect their emotions because sometimes you will find a man who will say anything and it's best to be prepared.
There are many, many decent men out there, lovely, but those who want to spend a night with you without even meeting you are not decent, whatever they say