It is likely a primitive instinct that you, as her guardian and defender, were able to console and protect her during a time of need, causing a rush of testosterone and a state of arousal. Or you just liked her **** pressed against you as she hugged you.

Some women don't understand this male problem. Before people jump down my throat, I said "some". Happens with my wife all the time too. I can't control it, and if I ever meet a guy who claims he can control it, he's either lying, or I want his autograph.

Simple physical, relatively intimate contact is why. Flesh is stupid. It does not understand context.

Hey hugging always does, no worries! Those are the perks of being a male flower, u don't need to be emotional to get a boner

Boners are like getting perky nipples, it's involuntary. :/

It's now the perfect time for apology sex.

Hey man, women get lady boners for no reason.. Only difference is ours can't be seen or felt through clothing... Your lady needs to think about that

I submitted an FML dead on to this yesterday morning. Coincidence...?

if a guy did that with me I'd be complimented haha, plus I get randy when I'm sad

Happens to my boyfriend every time I cry. I've gotten used to it by now haha.