He's only nervous because he wants you to like his family and his family to like you. If him being nervous is upsetting you, then talk to him about it. Tell him to be himself, calm down, etc.
Talk to him/her and he/she may get less shy around you
It either means: a) That she is very shy, and feels more comfortable with her brother or b) That she has close family links
If this crush has feelings for you they may be shy about expressing them. They're not shy around others when you're around because they feel like it's not as akward as being alone.
It means that one of them is lying or your crush is shy to say it
It may be because she really like you and now that she has feelings for you, she is more shy.
she is probably too scared to ruin your relationship. I was like that once, but i started to become closer to her family.
yes,he has a little crush on her
He's shy, nervous and embaresses
Just be yourself. If you're shy, so be it. You will always get the most mileage out of being yourself.
I'm only shy around people I don't know, or attractive guys. (my crush) They act normally, shy people do talk, maybe it's at home, or with a really good friend.
he's probably shy try and talk about something that hes interested in to break the ice he'll ease up a little
If she is shy then this would make sense. It all goes down to the basics of how her day turns out really. If her crush talks to her or makes her feel good she will be happy until she gets home and starts getting bugged by everybody about it, possibly. Or she could be all nice with the family and then get around her crush and he does something she knows nobody in her family would do and finds it unsuitable.