What are the symptoms of a boy being in love?

Question

Are there any signs?

Answer 1

They get a hard-on.

On a more serious note, all I can say is that dudes act strangely whenever you look at them, they may turn away, etc.

Answer 2

he acts stupid and grins like crazy and gets nervous and sweaty

Answer 3

It often differs by the age of the boy.  Younger teen boys like to tease and make fun of the girl they like (while the girl just believes she's being hated on).  Older teen guys still do light teasing (or class clowning) to try to get the attention of the girl they like.  They will look at you, try to find time to talk to you, or get your opinion about something.  The shyer guys may just stare at you and then look quickly away.

College-age boys are a bit more communicative towards the girl they like.  They try to search for common interests or to engage you in a conversation.

Showing-off for all ages is a key hint that they like you.  But you know, the symptoms of love he is likely to display depends on the personality of the guy in question.  For a shyer guy, it may be harder to distinguish his feelings, since he is quiet and not as active in front of you, and may even appear nervous (which may seem like he doesn't like you).

One good thing to notice is if the guy is paying attention to you when you talk, and if he remembers things you talked about in previous conversations or if he remembers something you told him about yourself.  Just like girls do for the guys they like, guys also want to know more about the girls they like and will do their best to remember that info.