do all gay relationships end up sexless ?

when i hear people talking about friends in long term gay male relationships, almost all of them seem to be sexless ... which begs the questions:

i) what proportion of gay relationships do end up sexless ?

ii) is it higher for gay male relationships than for straights ?

any information either anecdotal or evidence based would be welcome !

how to say no ?

in the steam room at the gym yesterday, a guy started showing off his erection - we were the only ones there ... but i wasn't interested, so i tried looking away to demonstrate my indifference !

however, that didn't seem to stop him, he kept showing and rubbing his hardon ...

i didn't want to leave for the showers in case he followed me ... so what is the best way to say no ?