"...like to show his cock off after showering..." Could you elaborate on that? How are you in a situation to see him nude after a shower? Do you live together? Or belong to to the same gym? If the former, start hanging out around the house nude so you can give him a good look at your cock. If the latter, get an erection and see how he reacts.
By #147052 at 23,Aug,12 14:01
honesty is always the best way to go. If you want to become involved with him, just ask him why he keeps you in a state of excitement while he does his parade for you.
A very delicate question. Has he given you any hints or other indications that he's interested? By the way, he need not be gay to be interested. A lot of straight guys like to take friendship with their buddies up a notch to include sex. Have you dropped any hints that you're interested? If so, how did he react?