With dd...DH was for sure able to feel her moving at 18 weeks. This pg...DH was able to feel it for sure around 16 weeks. He can feel it best when I'm laying down in bed. My sister was able to feel the baby kicking at Thanksgiving while I sat at the kitchen table, and I was 21 weeks then.
With both of my babies I was for sure feeling them moving by 12 weeks. Although I gain a lot of weight when I'm pg...I'm normally on the thin side, and I think that might have something to do with it. At least, I've heard that it does and it seems to make sense to me.
Mandy