To go back to your original question - no, you're expecting far too little.
I hope this loser doesn't turn up... but I think he will. That in itself will tell you a massive amount. That his preferred method of sorting out problems is to sulk, tantrum, manipulate... but then turn up bright eyed and waiting for his dinner to be cooked as if nothing has happened. Meanwhile, your stomach has been in knots for a day.
With the rest - where to start? Lazy, entitled, selfish, a taker. You can do so much better it's not even funny. Your friend is 100% right about him.
This man will be an appalling role model for your DS.
He will also be thoroughly damaging for him as he grows - no, he clearly has no intention of stepping into the role of stepfather. He wants to be pandered to, not care for others.. that should be obvious.
The thing that stood out for me is his teasing of your DS. That is BAD BAD BAD. It's one of the things I REALLY hate seeing - you see (crap) parents doing it to their kids sometimes. No, it's never a case of 'them winding each other up' - even if your DS acts out back to him, the power balance is in your P's favour. When you were a kid, do you ever remember the feeling you got when an adult teased you? The discomfort and embarrassment that you were being taken for a ride in a way you couldn't ever really defend yourself against? The feeling is very similar to bullying - on the surface the bully is smiling and 'teasing' - but you are the weaker person and they know that, and their smile is really a smirk of triumph.
It's a horrible feeling. Your DS will be less secure, will come on less well with this nasty bloke around.
If he turns up this weekend, don't panic. Let him carry on with the way he is behaving, watch him... and learn. I hope it will make up your mind for you in a way 100 strangers on the internet can't. Mind you, so many strangers are not massively likely to be wrong...
When he leaves, dump. DUMP DUMP DUMP - and enjoy your time in Spain with your little boy, making new friends and having fun. Get yourself a trusted local babysitter and have a fab summer.