Huh?
I thought my problems ran deep.
Um, consider your options.
If you valued your girls opinion,
And you were a man.
You would KNOW, that the right thing to do is NOT go on your little cock sucking escapades while you're with her.
Cheating is Cheating, just because you feel like sucking some dick, like all the normal straight guys? doesn't mean it's not cheating.
That logic is ridiculous. I'm sorry.
If you cared about her, and her feelings, you'd drop it, and pray for your mind to clear up and not be craving cock.
That's just my opinion. It may come across as mean, but even people confused about their sexuality know right from wrong. (Not saying you are, because clearly you have no attraction to men.)
Tell you're older man, that he's not useful anymore and that your with someone.
Assuming you really do like her.
If not.
By all means, it's clear, go suck some cock behind her back and then kiss her.