Hmm...I have a teenaged daughter (ok three of them) and I think you might've hit the nail on the head when you said, " I think it has more to do with the fact we like him and he's a nice boy."

That might be exactly it. My middle daughter (she's 17) wouldn't dream of liking a guy I liked for her. If I so much as make a comment on how the guy looks or that he's nice, she'll instantly find something wrong with him. My youngest (Rottieluver) wants me to meet the guys she likes because she knows I'm cool.

Maybe if you became less interested or tried to point out the shortcomings of this guy, she'll start hanging out with him again.