Is it normal to feel this way about accents?

When my girlfirend is over, I like to get on XBOX live and talk to my british friends. I am Canadian. I am a male and I am 24 years old. I can only seem to get hard when I talk to them. They are both males. Their accent makes me soo hard. I am not gay though. I just get really hard when I am talking to them. I later take my frustration out on my girlfriend if she is around, but if she is not I will quietly (without them knowing) begin to masturbate. I sometimes pretend that I am not there so they will say my name. It seems to be the only way that I can 'finish'. IIN?