I get aroused

[Torchwatch]

You are lucky to have an environment in which arousal is accepted and not vilified. Your friends seem to accept your arousal and your close friends enjoy it.
Too many guys live in fear that any sign of arousal will result in homophobic bullying and harassment. Although we can arouse ourselves much of the time our members are on auto pilot and nature takes it's course without our being aware of it.
I don't think any part of a healthy human body is indecent, an aroused cock is exciting to view and causes arousal in others, but we should be careful not to force it upon other's whose feelings have to be respected.