How many dates to know if you should continue dating..

I (27F) have had 3 dates with a new guy (29M) who is really really nice. We chat endlessly have a laugh together but I’m not sure if I am feeling it. I’ve never been in a relationship where I have been treated well. So I don’t know if I’m not feeling it because this is alien to me, or because he’s not my type. We’ve arranged to have dinner at his on Saturday.. so I’m hoping it means we have sex basically to see if that ignites something in me. But would that make me an arsehole to sleep with him and then decide if I feel anything.. and call it off if I don’t?