Was he buying all the drinks? Were you with him when he ordered them?
I have no experience of being spiked personally bit it's happened to two good friends of mine and both times they deteriorated very quickly - babbling, incoherent, unable to stand or walk, vomiting, etc.
Luckily, both times they were looked after by friends and managed to get home safely.
If you can remember everything that happened then I'd say it's unlikely you were spiked with a drug. Although it's possible he was buying you bigger measures.
Tbh nothing else you're saying about him makes me think he's particularly sinister.
I don't think him leaving you alone at his place is especially weird. Asking to meet your son is overstepping a bit. And the thing about you being drunk and him not being a gentleman just sounds inept to me.
Added to the tightness, he's probably just a common or garden variety knob.
You sound a bit nervy. Whether it's because this guy is setting of your spidey senses for some reason, or you're out of practice with dating and want to avoid meeting dickheads, maybe there are some things you could do to make sure you feel a bit safer and in control when you're out dating. Like buying your own drinks, pre-arranging your own cab home, etc.